A History of Inventions, Discoveries, and Origins, Volume II (of 2)

Gas has also been manufactured from oil, rosin and other substances. Oil-gas is procured abundantly by the decomposition of oil, trickled into a red-hot retort, half-filled with coke or brick. It contains no sulphuretted hydrogen, requires no purification, and is much richer in carburetted hydrogen than coal-gas. Its expense has however led nearly to the entire disuse of this kind of gas.

In London there are eighteen public gas establishments and twelve companies; the capital invested in works and apparatus is estimated at 3,000,000l.]

NIGHT-WATCH

The establishment of those people who are obliged to keep watch in the streets of cities during the night, belongs to the oldest regulations of police. Such watchmen are mentioned in the Song of Solomon, and they occur also in the book of Psalms. Athens and other cities of Greece had at least sentinels posted in various parts; and some of the thesmothetæ were obliged to visit them from time to time, in order to keep them to their duty[456 - They were called bell-bearers or bellmen, because while going the rounds they gave a signal with their bells, which the sentinels were obliged immediately to answer. See the Scholiasts on the Aves of Aristophanes, ver. 841. Dio Cassius, lib. liv. 4, p. 773, says, “The watchmen in the different quarters of the city have small bells, that they may make signals to each other when they think proper.” The bells therefore did not serve for announcing the hours, as some have imagined.]. At Rome there were triumviri nocturni, cohortes vigilum, &c.

The object of all these institutions seems to have been rather the prevention of fires than the guarding against nocturnal alarms or danger; though in the course of time attention was paid to these also. When Augustus wished to strengthen the night-watch, for the purpose of suppressing nocturnal commotions, he used as a pretext the apprehension of fires only. The regulations respecting these watchmen, and the discipline to which they were subjected, were almost the same as those for night-sentinels in camps during the time of war; but it does not appear that the night-watchmen in cities were obliged to prove their presence and vigilance by singing, calling out, or by any other means. Signals were made by the patroles alone, with bells, when the watchmen wished to say anything to each other. Singing by sentinels in time of war was customary, at least among some nations; but in all probability that practice was not common in the time of peace[457 - The Persian sentinels sung in this manner when they were surprised in the city by the Romans. – Ammianus Marcell. xxiv. 15.].

Calling out the hours seems to have been first practised after the erection of city gates, and, in my opinion, to have taken its rise in Germany; though indeed it must be allowed that such a regulation would have been very useful in ancient Rome, where there were no clocks, and where people had nothing in their houses to announce the hours in the night-time. During the day people could know the hours after water-clocks had been constructed at the public expense, and placed in open buildings erected in various parts of the city. The case seems to have been the same in Greece; and rich families kept particular servants both male and female, whose business it was to announce to their masters and mistresses certain periods of the day, as pointed out by the city clocks. These servants consisted principally of boys and young girls, the latter being destined to attend on the ladies. It appears, however, that in the course of time water-clocks were kept also in the palaces of the great: at any rate Trimalchio, the celebrated voluptuary mentioned in Petronius, had one in his dining-room, and a servant stationed near it to proclaim the progress of the hours, that his master might know how much of his lifetime was spent; for he did not wish to lose a single moment without enjoying pleasure.

I have not read everything that has been written by others on the division of time among the ancients; but after the researches I have made, I must confess that I do not know whether the hours were announced in the night-time to those who wished and had occasion to know them. There were then no clocks which struck the hours, as has been already said; and as water-clocks were both scarce and expensive, they could not be procured by labouring people, to whom it was of most importance to be acquainted with the progress of time[458 - That the servants in many houses were wakened by the ringing of a bell, appears from what Lucian says in his treatise, De iis qui mercede conducti in divitum familiis vivunt, cap. xxiv. p. 245, and cap. xxxi. p. 254, Bipont edition, vol. iii. It does not however follow that there were then striking or alarm-clocks, as some have thence concluded. See Magius De Tintinnabulis, cap. 6, in Sallengre, Thesaurus Antiquit. ii. p. 1177.]. It would therefore have been a useful and necessary regulation to have caused the watchmen in the streets to proclaim the hours, which they could have known from the public water-clocks, by blowing a horn, or by calling out.

It appears, however, that people must have been soon led to such an institution, because the above methods had been long practised in war. The periods for mounting guard were determined by water-clocks; at each watch a horn was blown, and every one could by this signal know the hour of the night[459 - Vegetius De Re Milit. iii. 8. That Cæsar had such clocks may be concluded from the observation which he makes in his Commentaries, on the length of the day in the islands near Ireland, lib. v. 13. Maternus, in Romische Alterthümer, iii. p. 47, endeavours to prove by what Suetonius relates of Domitian, cap. 16, that this prince had in his palace neither a sun-dial nor a water-clock. But what kind of a proof! Domitian asked what the hour was, and some one answered, the sixth. Such insignificant dicta probantia have been banished from philosophy by the moderns, and ought they not to be banished from antiquities likewise? The often-quoted passage also of Valerius Maximus, viii. 7, 5, proves nothing, unless we first adopt the amendment of Green. Carneades, it is said, was so engaged in the study of philosophy, that he would have forgot his meals had not Melissa put him in mind of them. Green reads monitrix domestica; but Valerius says, “Melissa, quam uxoris loco habebat.” See Sallengre, Thes. Antiq. Rom. i. p. 721. A passage likewise in Pliny’s Epistles, iii. 1, p. 181, “ubi hora balinei nunciata est,” does not properly prove that it alludes to one of those boys who announced the hours. That such servants however were kept, is evident from the undoubted testimony of various authors. Martial, viii. ep. 67. – Juven. Sat. x. 216. – Seneca De Brevit. Vitæ, c. 12. – Alciphron, Epist. lib. iii. p. 282. – Sidon. Apollin. ii. ep. 9, p. 120.]; but I have met with no proof that these regulations were established in cities during the time of peace, though many modern writers have not hesitated to refer to the night-watch in cities what alludes only to nocturnal guards in the time of war. On the contrary, I am still more strongly inclined to think that ancient Rome was entirely destitute of such a police establishment. The bells borne by the night watchmen were used only by the patroles, as we are expressly told, or to give signals upon extraordinary occasions, such as that of a fire, or when any violence had been committed. Cicero, comparing the life of a civil with that of a military officer, says, “The former is awaked by the crowing of the cock, and the latter by the sound of the trumpet.” The former therefore had no other means of knowing the hours of the night but by attending to the noise made by that animal[460 - Cic. Orat. pro Muræna, cap. 22.]. An ancient poet says that the cock is the trumpeter which awakens people in the time of peace[461 - Sil. Ital. vii. 155.]. The ancients indeed understood much better than the vulgar at present, who are already too much accustomed to clocks, how to determine the periods of the night by observing the stars; but here I am speaking of capital cities, and in these people are not very fond of quitting their beds to look at the stars, which are not always to be seen.

Without entering into further researches respecting watchmen among the ancient Greeks and Romans, I shall prove, by such testimonies as I am acquainted with, that the police establishment of which I speak is more modern in our cities than one might suppose. But I must except Paris; for it appears that night-watching was established there, as at Rome, in the commencement of its monarchy. De la Mare[462 - Traité de la Police, vol. i. in the Index under the word Guet.] quotes the ordinances on this subject of Clothaire II., in the year 595, of Charlemagne, and of the following periods. At first the citizens were obliged to keep watch in turns, under the command of a miles gueti, who was called also chevalier. The French writers remark on this circumstance, that the term guet, which occurs in the oldest ordinances, was formed from the German words wache, wacht, the guard, or watch; and in like manner several other ancient German military terms, such as bivouac, landsquenet, &c.[463 - Bivouac, from the German beiwacht, is an additional night-guard during a siege, or when an army is encamped near the enemy. Lansquenets were German soldiers added by Charles VIII. of France to his infantry, and who were continued in the French army till Francis I. introduced his legions. – Trans.] have been retained in the French language. In the course of time, when general tranquillity prevailed, a custom was gradually introduced of avoiding the duty of watching by paying a certain sum of money, until at length permanent compagnies de guet were established in Paris, Lyons, Orleans, and afterwards in other cities.

If I am not mistaken, the establishment of single watchmen, who go through the streets and call out the hours, is peculiar to Germany, and was copied only in modern times by our neighbours. The antiquity of it however I will not venture to determine[464 - [With respect to the institution of night-watch in this country, Stow says, “For a full remedy of enormities in the night, I read, that in the year 1253 Henry III. commanded watches in the cities and borough towns to be kept, for the better observing of peace and quietness among his people… And further, by the advice of them of Savoy, he ordained, that if any man chanced to be robbed, or by any means damnified by any thief or robber, he to whom the charge of keeping that country, city, or borough, chiefly appertained, where the robbery was done, should competently restore the loss. And this was after the use of Savoy, but yet thought more hard to be observed here than in those parts; and therefore, leaving those laborious watches, I will speak of our pleasures and pastimes in watching by night.” (Survey of London, Thoms’s edition, 1842, p. 39.) He then describes the marching watches which were instituted in the months of June and July, on the vigils and evenings of festival days; with the cresset lights, &c. But he does not state whether these watches were continued in his time; nor does he state the author of the information which he gives us from his reading. The statute of Winchester, 13 Edward I. c. 4, enforces a continuation of the watches as they had previously been made, from Ascension-day to Michaelmas-day; the night-watch from sun-set to sunrise, in every city by six men at each gate, in every borough by twelve men, in every open town by six or four men.]]. At Berlin, the elector John George appointed watchmen in the year 1588[465 - Nicolai Beschreib. von Berlin, i, p. 38.]; but in 1677 there were none in that capital, and the city officers were obliged to call out the hours[466 - Ib. p. 49.]. Montagne, during his travels in 1580, thought the calling out of the night-watch in the German cities a very singular custom. “The watchmen,” says he, “went about the houses in the night-time, not so much on account of thieves as on account of fires and other alarms. When the clocks struck, the one was obliged to call out aloud to the other, and to ask what it was o’clock, and then to wish him a good night[467 - Iter Germanicum. Hamburgi, 1717, 8vo, p. 26.].” This circumstance he remarks also when speaking of Inspruck. Mabillon likewise, who made a literary tour through Germany, describes calling out the hours as a practice altogether peculiar to that country.

The horn of our watchmen seems to be the buccina of the ancients, which, as we know, was at first an ox’s horn, though it was afterwards made of metal[468 - Lipsius De Milit. Rom. iv. 10, p. 198. – Bochart. Hierozoic. i.]. Rattles, which are most proper for cities, as horns are for villages, seem to be of later invention[469 - From the name of this instrument, called in some places of Germany a ratel, arose the appellation of ratelwache, which was established at Hamburg in 1671. In the Dutch language the words ratel, ratelaar, ratelen, ratelmann, ratelwagter (a night-watchman), are quite common.]. The common form, “Hear, my masters, and let me tell you,” is very old. I am not the only person to whom this question has occurred, why it should not rather be, “Ye people, or citizens.” The chancellor von Ludwig deduces it from the Romans, who, as he says, were more liberal with the word Master, like our neighbours with Messieurs, than the old Germans; but the Roman watchmen did not call out, nor yet do the French at present. If I may be allowed a conjecture on so trifling an object, I should say that the city servants or beadles were the first persons appointed to call out the hours, as was the case at Berlin. These therefore called out to their masters, and “Our masters” is still the usual appellation given to the magistrates in old cities, particularly in the central and southern portions of Germany, and in Switzerland. At Göttingen the ancient form was abolished in the year 1791, and the watchmen call out now, “The clock has struck ten, it is ten o’clock.”

Watchmen who were stationed on steeples by day as well as by night, and who, every time the clock struck, were obliged to give a proof of their vigilance by blowing a horn, seem to have been first established on a permanent footing in Germany, and perhaps before watchmen in the streets. In England there are none of these watchmen; and in general they are very rare beyond the boundaries of Germany. That watchmen were posted on the tops of towers, in the earliest ages, to look out for the approach of an enemy, is well known. In the times of feudal dissension, when one chief, if he called in any assistance, could often do a great deal of hurt to a large city, either by plundering and burning the suburbs and neighbouring villages, or by driving away the cattle of the citizens, and attacking single travellers, such precaution was more necessary than at present. The nobility therefore kept in their strong castles watchmen, stationed on towers; and this practice prevailed in other countries besides Ireland and Burgundy[470 - Stanihurst De Rebus in Hibernia Gestis, lib. i. p. 33.]. It appears by the laws of Wales, that a watchman with a horn was kept in the king’s palace[471 - Leges Walliæ. Lond. 1730, fol.]. The German princes had in their castles, at any rate in the sixteenth century, tower-watchmen, who were obliged to blow a horn every morning and evening.

At first, the citizens themselves were obliged to keep watch in turns on the church-steeples, as well as at the town-gates; as may be seen in a police ordinance of the city of Einbeck[472 - The person whose turn it was to watch at the gates, was obliged to perform the duty himself, or to cause it to be performed by a fit and proper young citizen. Those who attended to trade and neglected the watch, paid for every omission one mark to the council. The case was the same with the watch on the tower in the market-place.], in the year 1573. It was the duty of these watchmen, especially where there were no town clocks, to announce certain periods, such as those of opening and shutting the city-gates. The idea of giving orders to these watchmen to attend not only to danger from the enemy but from fire also, and, after the introduction of public clocks, to prove their vigilance by making a signal with their horn, must have naturally occurred; and the utility of this regulation was so important, that watchmen on steeples were retained, even when cities, by the prevalence of peace, had no occasion to be apprehensive of hostile incursions.

After this period persons were appointed for the particular purpose of watching; and small apartments were constructed for them in the steeples. At first they were allowed to have their wives with them; but this was sometimes prohibited, because a profanation of the church was apprehended. In most, if not in all cities, the town-piper, or as we say at present, town-musician, was appointed steeple-watchman; and lodgings were assigned to him in the steeple; but in the course of time, as these were too high and too inconvenient, a house was given him near the church, and he was allowed to send one of his servants or domestics to keep watch in his stead. This is the case still at Göttingen. The city musician was called formerly the Hausmann, which name is still retained here as well as at the Hartz, in Halle, and several other places; and the steeple in which he used to dwell and keep watch was called the Hausmann’s Thurm[473 - In the Berlin police ordinance of the year 1580, it was ordered that the Raths-thurn oder Hausmann, steeple-watchman or city-musician, should attend at weddings with music for the accustomed pay, but only till the hour of nine at night, in order that he might then blow his horn on the steeple, and place the night-watch.]. These establishments, however, were not general; and were not everywhere formed at a period equally early, as will be shown by the proofs which I shall here adduce.

If we can credit an Arabian author, whose Travels were published by Renaudot, the Chinese were accustomed, so early as the ninth century, to have watchmen posted on towers, who announced the hours of the day as well as of the night, by striking or beating upon a suspended board. Marco Paulo, who, in the thirteenth century, travelled through Tartary and China, confirms this account; at least in regard to a city which he calls Quinsai, though he says that signals were given only in cases of fire and disturbance. Such boards are used in China even at present[474 - Martini Atlas Sinens. p. 17. Matches or links, to which alarums are sometimes added, are employed in China to point out the hours; and these are announced by watchmen placed on towers who beat a drum. See Kæmpfer’s Japan, where the mention of matches is omitted. Thunberg says, “Time is measured here not by clocks or hour-glasses, but by burning matches, which are plaited like ropes, and have knots on them. When the match burns to a knot, which marks a particular lapse of time, the hour is announced, during the day, by a certain number of strokes on the bells in the temples; and in the night by watchmen who go round and give a like signal with two pieces of board, which they knock against each other.”]; and in Petersburg the watchmen who are stationed at single houses or in certain parts of the city, are accustomed to announce the hours by beating on a suspended plate of iron. Such boards are still used by the Christians in the Levant to assemble people to divine service, either because they dare not ring bells or are unable to purchase them. The former is related by Tournefort of the inhabitants of the Grecian islands, and the latter by Chardin of the Mingrelians. The like means were employed in monasteries, at the earliest periods, to give notice of the hours of prayer, and to awaken the monks[475 - A great deal of important information, which is as yet too little known, has been collected on this subject by Reiske, on Constantini Lib. de Ceremoniis Aulæ Byzant. ii. p. 74.]. Mahomet, who in his form of worship borrowed many things from the Christians of Syria and Arabia, adopted the same method of assembling the people to prayers; but when he remarked that it appeared to his followers to savour too much of Christianity, he again introduced the practice of calling out.

The steeple-watchmen in Germany are often mentioned in the fourteenth and fifteenth centuries. In the year 1351, when the council of Erfurt renewed that police ordinance which was called the Zuchtbrief, letter of discipline, because it kept the people in proper subjection, it was ordered, besides other regulations in regard to fire, that two watchmen should be posted on every steeple. A watchman of this kind was appointed at Merseburg and Leisnig so early as the year 1400. In the beginning of the seventeenth century the town-piper of Leisnig lived still in apartments in the steeple. In the year 1563, a church-steeple was erected in that place, and an apartment built in it for a permanent watchman, who was obliged to announce the hours every time the clock struck.

In the fifteenth century the city of Ulm kept permanent watchmen in many of the steeples. In the year 1452 a bell was suspended in the tower of the cathedral of Frankfort-on-the-Maine, which was to be rung in times of feudal alarm, and all the watchmen on the steeples were then to blow their horns and hoist their banners. In the year 1476, a room for the watchman was constructed in the steeple of the church of St. Nicholas. In the year 1509, watchmen were kept both on the watch-towers and steeples, who gave notice by firing a musket when strangers approached. The watchman on the tower of the cathedral immediately announced, by blowing a trumpet, whether the strangers were on foot or on horseback; and at the same time hung out a red flag towards the quarter in which he observed them advancing. The same watchman was obliged, likewise, to blow his horn on an alarm of fire; and that these people might be vigilant day and night, both in winter and summer, the council supplied them with fur-cloaks, seven of which, in the above-mentioned year, were purchased for ten florins and a half.

In the year 1496, the large clock was put up in the steeple of Oettingen, and a person appointed to keep watch on it[476 - This is related in the Oettingisches Geschichts-almanach, p. 7, on the authority of an account in the parish books of Oettingen, said to be extracted from an ancient chronicle of that town. The author of this almanac, which is now little known, was, as I have been told, Schablen, superintendant at Oettingen.]. In 1580, Montagne was much surprised to find on the steeple at Constance a man who kept watch there continually; and who, on no account, was permitted to come down from his station.

[One of the greatest improvements of modern times, in this country, is the establishment of that highly efficient body, the new police. The first introduction of the police was made by the magistrates of Cheshire in 1829, under an authority from parliament (Act 10 Geo. IV. c. 97). The first metropolitan establishment was also made in 1829. Before this time the total old force of the metropolitan watchmen consisted of 797 parochial day officers, 2785 night-watch, and upward of 100 private watchmen; including the Bow-street day and night patrol, there were about 4000 men employed in the district stretching from Brentford Bridge on the west to the river Lea on the east, and from Highgate on the north to Streatham on the south, excluding the city of London. The act of parliament creating the new police force (10 Geo. IV. c. 44) placed the control of the whole body in the hands of two commissioners, who devote their whole time to their duties. The total number of the metropolitan police in January 1840 consisted of 3486 men. These are arranged in divisions, each of which is employed in a distinct district. The metropolis is divided into “beats” and is watched day and night. Since August 1839, the horse-patrol, consisting of seventy-one mounted men, who are employed within a distance of several miles around London, has been incorporated with the metropolitan police. The Thames police consists of twenty-one surveyors, each of whom has charge of three men and a boat when on duty. The establishment is under the immediate direction of the magistrates of the Thames police-office.

The police affairs of the city of London are still under its own management. In 1833, the number of persons employed in the several wards of the city was, – ordinary watchmen, 500; superintending watchmen, 65; patrolling watchmen, 91; beadles, 54; total, 710. There are about 400 men doing duty in the city at midnight. In addition to the paid watchmen, about 400 ward-constables are appointed. The expense of the day-police, consisting of about 120 men, amounts to about £9000 a year, and is defrayed by the corporation: and the sum levied on the wards for the support of the night-watch averages about £42,000 per annum.

The police of the metropolis and the district within fifteen miles of Charing Cross (exclusive of the city) is regulated by the acts 10 Geo. IV. c. 44, and 2 and 3 Vict. c. 47. In nearly all the boroughs constituted under the Municipal Reform Act, a paid police force has been established on the same footing as the metropolitan police.]

PLANT-SKELETONS

Plants, as well as animals, are organised bodies, and like them their parts may be dissected and decomposed by art; but the anatomy of the former has not been cultivated so long and with so much zeal and success as that of animals. Some naturalists, about the beginning of the last century, first began to make it an object of attention, to compare the structure of plants with that of animals; and for that purpose to employ the microscope. Among these, two distinguished themselves in a particular manner; Marcellus Malpighi, an Italian; and Nehemiah Grew, an Englishman; who both undertook almost the same experiments and made them known at the same time; so that it is impossible to determine which of them was the earlier. It appears, however, that Grew published some of his observations a little sooner; but Malpighi was prior in making his known in a complete manner. But even allowing that the one had received hints of the processes of the other, they are both entitled to praise that each made experiments of his own, and from these prepared figures, which are always more correct the nearer they correspond with each other.

Among the various helps towards acquiring a knowledge of the anatomy of plants, one of the principal is the art of reducing to skeletons leaves, fruit and roots; that is, of freeing them from their soft, tender and pulpy substance, in such a manner, that one can survey alone their internal, harder vessels in their entire connexion. This may be done by exposing the leaves to decay for some time soaked in water, by which means the softer parts will be dissolved, or at least separated from the internal harder parts, so that one, by carefully wiping, pressing and rinsing them, can obtain the latter alone perfectly entire. One will possess then a tissue composed of innumerable woody threads or filaments, which, in a multiplicity of ways, run through and intersect each other. By sufficient practice and caution one may detach, from each side of a leaf, a very thin covering, between which lies a delicate web of exceedingly tender vessels. These form a woody net-work, between the meshes of which fine glandules are distributed. This net is double, or at least can be divided lengthwise into halves, between which may be observed a substance that appears as it were to be the marrow of the plant. Persons who are expert often succeed so far, with many leaves, as to separate the external covering on both sides from the woody net, and to split the latter into two, so that the whole leaf seems to be divided into four.

One might conjecture that this method of reducing leaves to skeletons must have been long known, as one frequently finds in ponds leaves which have dropped from the neighbouring trees, and which by decomposition, without the assistance of art, have been converted into such a woody net-work, quite perfect and entire. It is however certain that a naturalist, about the year 1645, first conceived the idea of employing decomposition for the purpose of making leaf-skeletons, and of assisting it by ingenious operations of art.

This naturalist, Marcus Aurelius Severinus, professor of anatomy and surgery at Naples, was born in 1580, and died of the plague in 1656. In his Zootomia Democritæa, printed in 1645, he gave the figure, with a description of a leaf of the Ficus Opuntia reduced to a skeleton. Of the particular process employed to prepare this leaf, the figure of which is very coarse and indistinct, he gives no account. He says only that the soft substance was so dissolved that the vessels or nerves alone remained; and that he had been equally successful with a leaf of the palm-tree. A piece of a leaf of the like kind he sent by Thomas Bartholin to Olaus Wormius, who caused it to be engraved on copper, in a much neater manner, without saying anything of the method in which it had been prepared[477 - Museum Wormianum. Lugd. Bat. 1655, fol. p. 149.]. The process Severin kept secret; but he communicated it to Bartholin, in a letter, on the 25th of February 1645, on condition that he would not disclose it to any one. At that period, however, it excited very little attention, and was soon forgotten, though in the year 1685 one Gabriel Clauder made known that he had reduced vine-leaves, the calyx of the winter cherry, and a root of hemlock, to a net or tissue by burying them in sand during the heat of summer, and hanging them up some months in the open air till they were completely dried.

This art was considered to be of much more importance when it was again revived by the well-known Dutchman, Frederick Ruysch. That naturalist found means to conduct all his undertakings and labours in such a manner as to excite great wonder; but we must allow him the merit of having brought the greater part of them to a degree of perfection which no one had attained before. By the anatomy of animals, in which he was eminently skilled, he was led to the dissection of plants; and as it seemed impossible to fill their tender vessels, like those of animals, with a coloured solid substance[478 - The well-known Sir John Hill, an Englishman, has proved, however, in later times, the possibility of injecting a substance into the vessels of plants also. He dissolved sugar of lead in water, suspended in it bits of the finest wood, so that one-half of them was under water and the other above it, and covered the vessel in which they were placed with an inverted glass. At the end of two days he took the bits of wood out, cut off the parts which had been immersed in the water, dipped them in a warm lye made of unslaked lime and orpiment, like what was used formerly for proving wine; and by these means the finest vessels, which had been before filled with sugar of lead, acquired a dark colour, and their apertures became much more distinct. This process he describes himself in his work on the Construction of Timber.], he fell upon a method of separating the hard parts from the soft, and of preserving them in that manner.

For this purpose he first tried a method which he had employed with uncommon success, in regard to the parts of animals. He covered the leaves and fruit with insects, which ate up the soft or pulpy parts, and left only those that were hard. But however well these insects, which he called his little assistants, may have executed their task, they did not abstain altogether from the solid parts, so that they never produced a complete skeleton. He dismissed them, therefore, and endeavoured to execute with his own fingers what he had before caused the insects to perform, after he had separated the soft parts from the hard by decomposition. In this he succeeded so perfectly, that all who saw his skeletons of leaves or fruit were astonished at the fineness of the work and wished to imitate them.

I cannot exactly determine the year in which Ruysch began to prepare these skeletons. Trew thinks that it must have been when he was in a very advanced age, or at any rate after the year 1718; for when he was admitted to Ruysch’s collection in that year, he observed none of these curiosities. Rundmann, however, saw some of them in his possession in the year 1708[479 - Rariora Naturæ et Artis. Breslau and Leipsic, 1737, fol. p. 421.]. At first Ruysch endeavoured to keep the process a secret, and to evade giving direct answers to the questions of the curious. We are informed by Rundmann, that he attempted to imitate his art by burying leaves at the end of harvest in the earth, and leaving them there till the spring, by which their soft parts became so tender that he could strip them off with the greatest ease. He produced also the same effect by boiling them.

The first account which Ruysch himself published of his process, was, as far as I know, in the year 1723. After he had sufficiently excited the general curiosity, he gave figures of some of his vegetable skeletons, related the whole method of preparing them, and acknowledged that he had accidentally met with an imperfect engraving of a leaf-skeleton in the Museum of Wormius, which had at one time occasioned much wonder[480 - Adversariorum decas iii. in Ruyschii Opera Omnia Anat. Med.]. It is not improbable that he knew how the Italian, whom he does not mention, though he is mentioned by Wormius, and though he must certainly have been acquainted with his Zootomia, prepared his skeletons. I must however observe, that it is remarked by those who knew Ruysch, that he had read few books, and was very little versed in the literature of his profession.

In the year following, Ruysch described more articles of the like kind, and gave figures of some pears prepared in this manner. In 1726, when Vater, professor at Wittenberg, expressed great astonishment at the fineness of his works, he replied, in a letter written in 1727, that he had at first caused them to be executed by insects, but that he then made them himself with his fingers[481 - A. Vateri Epist. ad Ruyschium de Musculo Orbiculari, 1727. Of employing different kinds of insects, particularly the dermestes, as they are called, for reducing animal and vegetable bodies to skeletons, Hebenstreit has treated in Program. de Vermibus Anatomicorum administris. Lips. 1741. Figures of the insects and of some of their preparations are added.]. He repeated the same thing also in 1728, when he described and gave engravings of more of these curious objects[482 - Acta Eruditorum, 1729, Febr. p. 63.]. The progress of this invention is related in the same manner by Schreiber, in his Life of Ruysch.

When the method of producing these skeletons became publicly known, they were soon prepared by others; some of whom made observations, which were contrary to those of Ruysch. Among these in particular were J. Bapt. Du Hamel, who, so early as the year 1727, described and illustrated with elegant engravings the interior construction of a pear[483 - Mémoires de l’Acad. des Sciences, ann. 1730, 1731, 1732.]; Trew[484 - Commerc. Litter. Norim. 1732, p. 73.], in whose possession Keysler saw such skeletons in 1730; P. H. G. Mohring[485 - Ib.]; Seba[486 - Phil. Transact. 1730, ccccxvi. p. 441.]; Francis Nicholls[487 - Ib. ccccxiv. p. 371.], an Englishman; Professor Hollmann[488 - Ib. cccclxi. p. 789, and cccclxiii. p. 796. – Commerc. Litter. Norimb. 1735, p. 353.] at Göttingen, Ludwig[489 - Institutiones Regni Vegetabil. In the part on Leaves.], Walther[490 - Programma de Plantarum Structura. Lips. 1740, 4to, § 5, 6.], Gesner[491 - Dissertat. Phys. de Vegetabilibus, printed with Linnæi Orat. de Necessitate Peregrinat. intra Patriam. Lugd. B. 1743.] and others. Nicholls seems to have been the first who split the net of an apple- or a pear-tree leaf into two equal parts, though Ruysch split a leaf of the opuntia into three, four, and even five layers, as he himself says.

In the year 1748, Seligmann, an engraver, began to publish, in folio plates, figures of several leaves which he had reduced to skeletons[492 - Die Nahrungs-Gefässe in den Blättern der Bäume. Nurnb. 1748.]. As he thought it impossible to make drawings sufficiently correct, he took impressions from the leaves or nets themselves, with red ink, and in a manner which may be seen described in various books on the arts. Of the greater part he gave two figures, one of the upper and another of the under side. He promised also to give figures of the objects as magnified by a solar microscope; and two plates were to be delivered monthly. Seligmann however died soon after, if I am not mistaken; and a lawsuit took place between his heirs, by which the whole of the copies printed were arrested, and for this reason the work was never completed, and is to be found only in a very few libraries.

Cobres says that eight pages of text, with two black and twenty-nine red copper-plates, were completed. The copy which is in the library of our university has only eight pages of text, consisting partly of a preface by C. Trew, and partly of an account of the author, printed in Latin and German opposite to each other. Trew gives a history of the physiology of plants and of leaf-skeletons; and Seligmann treats on the methods of preparing the latter. The number of the plates however is greater than that assigned by Cobres. The copy which is now before me contains thirty-three plates, printed in red; and besides these, two plates in black, with figures of the objects magnified. Of the second plate in red, there is a duplicate with this title, “Leaves of a bergamot pear-tree, the fruit of which is mild;” but the figures in both are not the same; and it appears that the author considered one of the plates as defective, and therefore gave another. The leaves represented in the plates are those of the orange-tree, lemon-tree, shaddock-tree, butcher’s-broom, walnut-tree, pear-tree, laurel, lime-tree, ivy, medlar, chestnut-tree, maple-tree, holly, willow, white hawthorn, &c.

I shall take this opportunity of inserting here the history of the art of raising trees from leaves. The first who made this art known was Agostino Mandirola, doctor of theology, an Italian minorite of the Franciscan order. In a small work upon Gardening, which, as I think, was printed for the first time at Vicenza, in duodecimo, in the year 1652, and which was reprinted afterwards in various places, he gave an account of his having produced trees from the leaves of the cedar- and lemon-tree[493 - Many editions of this book may be found mentioned in Halleri Bibl. Botan. i. p. 484; Böhmeri Bibl. Hist. Nat. iii. p. 679.]; but he does not relate this circumstance as if he considered it to be a great discovery. On the contrary, he appears rather to think it a matter of very little importance. His book was soon translated into German; and his account copied by other writers, such as Böckler[494 - Haus- und Feld-Schule, i. 26.] and Hohberg[495 - Georgica Curiosa, i. p. 787.], who were at that time much read. A gardener of Augsburg, as we are told by Agricola, was the first who imitated this experiment, and proved the possibility of it to others. He is said to have tried it with good success in the garden of count de Wratislau, ambassador at Ratisbon from the elector of Bohemia.

But never was this experiment so often and so successfully repeated as in the garden of baron de Munchhausen, at Swobber. A young tree was obtained there from a leaf of the Limon a Rivo, which produced fruit the second year. It was sent to M. Volkamer, at Nuremberg, who caused a drawing to be made from it, which was afterwards engraved, in order that it might be published in the third volume of his Hesperides; but as the author died too early, it was not printed. The exact drawing, as it was then executed at Nuremberg, and an account of the whole process employed in the experiment at Swobber, have been published by the baron de Munchhausen himself, from authentic papers in his grandfather’s own writing[496 - Hausvater, vol. v. p. 662.].

No one, however, excited so much attention to this circumstance as the well-known George Andrew Agricola, physician at Ratisbon, who, with that confidence and prolixity which were peculiar to him, ventured to assert that trees could be propagated in the speediest manner by planting the leaves, after being steeped in a liquor which he had invented; and for the truth of his assertion he referred to his own experiments[497 - Versuch der Universal-vermehrung aller Bäume. Regensb. 1716, fol., or the edition by Brauser. Regensb. 1772.]. Among the naturalists of that period none took more trouble to examine the possibility of this effect than Thummig[498 - Thummigii Meletemata. Brunsw. 1727, 8vo, p. 5.], who endeavoured to prove that not only leaves with eyes left to them, could, in well-moistened earth, throw out roots which would produce a stem, but that leaves also without eyes would grow up to be trees. Baron Munchhausen, on the other hand, assures us, that according to the many experiments made in his garden, one can only expect young plants from the leaves of those trees which do not bring forth buds; that experiments made with the leaves of the lemon-tree had alone succeeded, but never those made with the leaves of the orange- or lime-tree; and that Agricola and Thummig had erroneously imagined that the leaves themselves shot up into trees, their middle fibre (rachis) becoming the stem, and the collateral fibres the branches. But the leaf decays as soon as it has resigned all its sap to the young tree, which is springing up below it.

To conclude: It is probable that the well-known multiplication of the Indian fig, or Opuntia, gave the first idea of this experiment; for every joint of that plant, stuck into the earth, and properly nurtured, throws out roots and grows. As these joints were commonly considered to be leaves, people tried whether other leaves would not grow in the like manner. Luckily, those of the lemon-tree were chosen for this purpose; and what was expected took place. Thus from a false hypothesis have new truths often been derived; and thus was Kepler, by a false and even improbable opinion, led to an assertion, afterwards confirmed, that the periodical revolutions of the planets were in proportion to their distance from the sun. But the raising of trees from leaves was too rashly declared to be a method that might be generally employed; for it is certain that it now seldom succeeds.

[Beckmann certainly overrates the value of these plant-skeletons in assisting the acquirement of a knowledge of the anatomy of plants. By macerating plants in water, all but the woody fibres are decomposed by the putrefactive fermentation which ensues. From an examination of these, a knowledge of structure merely is attainable, which may be now truly said to be thoroughly understood. It gives us no insight into its functions. The modern microscope has revealed to us the structure of all the components of vegetable tissues, and has most materially assisted in developing the functions of several; many, however, remain in the hands of the physiologist. Nevertheless, these plant-skeletons exhibit the true course and arrangement of the woody fibres, and form most beautiful objects. The leaves are not the only parts which can be thus prepared; the petals of many plants are even more delicate and beautiful in their ligneous structure, as evidenced in the hydrangea and several others. Their preparation is exceedingly simple, but tedious, and can only be well effected by maceration in water, which frequently requires to be considerably prolonged. The pulpy half-decomposed portions are gradually removed by a camel-hair pencil, or other means, with great delicacy and care; they are finally washed and bleached, if necessary, with chloride of lime or soda. By washing in considerably diluted muriatic acid and water, all traces of this reagent are removed; they are then dried, and will keep for an indefinite period.]

BILLS OF EXCHANGE

I shall not here repeat what has been collected by many learned men respecting the important history of this noble invention, but only lay before my readers an ordinance of the year 1394, concerning the acceptance of bills of exchange, and also two bills of the year 1404, as they may serve to illustrate further what has been before said on the subject by others. These documents are, indeed, more modern than those found by Raphael de Turre[499 - Disp. i. quæst. 4. n. 23.] in the writings of the jurist Baldus[500 - Consil. 348.], which are dated March 9, 1328; but they are attended with such circumstances as sufficiently prove that the method of transacting business by bills of exchange was fully established so early as the fourteenth century; and that the present form and terms were even then used. For this important information I am indebted to Von Martens, who found it in a History, written in Spanish, of the maritime trade and other branches of commerce at Barcelona, taken entirely from the archives of that city, and accompanied with documents from the same source, which abound with matter highly interesting[501 - Memorias Historicas sobre la Marina Commercio, etc. de Barcelona, por D. Ant. de Capmany. Madrid, 1779, 2 vols. 4to. The following important articles will be found in this work: – A custom-house tariff, written in Latin, of the year 1221, in which occur a great number of remarkable names and articles of merchandise not explained. Another of the like kind, of the year 1252. Letters of power to appoint consuls in distant countries, such as Syria, Egypt, &c., dated in the years 1266, 1268, and 1321. An ordinance of the year 1458, respecting insurance, which required that under-writing should be done in the presence of a notary, and declared polices o scriptures privades to be null and void. A privilegium of the emperor Andronicus II. to the merchants of Barcelona, written in Greek and Spanish, in 1290. Account of the oldest Spanish trade with wool, silk, salt, and saffron; and of the oldest guilds or incorporated societies of tradesmen at Barcelona, &c.].

Among these is an ordinance issued by the city of Barcelona in the year 1394, that bills of exchange should be accepted within twenty-four hours after they were presented; and that the acceptance should be written on the back of the bill[502 - Vol. ii. p. 382.].

In the year 1404, the magistrates of Bruges, in Flanders, requested the magistrates of Barcelona to inform them what was the common practice, in regard to bills of exchange, when the person who presented a bill raised money on it in an unusual manner, in the case of its not being paid, and by these means increased the expenses so much that the drawer would not consent to sustain the loss. The bill which gave occasion to this question is inserted in the memorial. It is written in the short form still used, which certainly seems to imply great antiquity. It speaks of usance; and it appears that first and second bills were at that time drawn, and that when bills were not accepted, it was customary to protest them.

[It may not, perhaps, be uninteresting to the reader to give a short account of the present mode of conducting transactions of bills of exchange; this we condense from Waterston’s Encyclopædia of Commerce, which contains the most recent and practical account.

The individual who issues the bill is called the drawer, the person to whom it is addressed the drawee, until he consent to honour the draft or obey the order or bill, by writing his name on the face of it, after which he is called the acceptor. The bill may be passed from hand to hand by delivery or indorsation, and in the latter case the person who makes over is called the indorser, and the person who receives the indorsee. The indorser commonly puts his name on the back, with or without a direction to pay to a particular person. He who is in legal possession of the bill and the obligation contained in it, is called the holder or the payee. There is no particular form for a bill of exchange required by law, further than that the mandate to pay in money be distinct, and the person who is to pay, the person who is to receive, and the time of payment shall be ascertainable beyond a doubt. By special statute in England, all bills under 20s. are void; and those between that sum and £5 must be made payable within twenty-one days after date, contain the name and description of the payee, and bear date at the time of making. Bills of exchange must be on a proper stamp.

Bills, though they are of the nature of a “chose in action,” which is not strictly assignable, may be transferred from hand to hand or negociated. To allow of this, there must be negotiable words, as “or order” or “bearer.” The various parties upon a bill, besides the acceptors, indorsers, drawers and others, become liable for its payment on failure of the acceptor.

Bills of exchange cease in England to be documents of debt on the expiration of six years from the time named for payment.

In foreign bills, the term “usance” is sometimes employed to express the period of running in foreign bills. It means a certain time fixed by custom, as between any two places. An usance between this kingdom and Rotterdam, Hamburg, Altona, or Paris, or any place in France, is one calendar month from the date of the bill; an usance between us and Cadiz, Madrid or Bilboa, two; an usance between us and Leghorn, Genoa, or Venice, three.]

TIN. TINNING

It is generally believed that the metal called at present tin was known and employed in the arts, not only in the time of Pliny, but as early as that of Herodotus, Homer, and Moses. This I will not venture to deny; but I can only admit that it is probable, or that the great antiquity of this metal cannot be so fully proved as that of gold, silver, copper, iron, lead, and quicksilver.