xxxi. 10.
1211
xxxi. 7. Here express mention is made of brine.
1212
Taciti Annal. xiii. 57.
1213
Lib. xxx. 7.
1214
This is particularly the case in regard to Aristot. Auscult. Mirab., as I have remarked in the preface to my edition.
1215
In the island of Dagebull, and also in Faretoft and Galmesbull, Frisio salt is made in the following manner. The inhabitants proceed along the coast in small vessels, and at low water go on shore on the mud, which they dig up till they come to a kind of earth called torricht; it is of a turfy nature, and interwoven with roots. This earth they convey to the islands, where they spread it out in the sun and leave it to dry, after which it is formed into a heap and burnt to ashes. What remains is again spread out, moistened and trod upon with the naked feet; the small stones and other useless parts are picked out, and being again dried and besprinkled with water, the ley is put into salt-pans and boiled into salt.
1216
Mémoires de l’Acad. de Bruxelles, 1777, i. p. 345.
1217
Elementa Chemiæ. Lugd. Bat. 1732, 4to, i. p. 767.
1218
Boyle considered the words of Solomon as a proof that nether must be fixed alkali; and he was the more convinced of it when he saw nitre obtained from Egypt effervesce with acids.
1219
See the History of Soap (#soap) in vol. i.
1220
Plin. xxxvi. 26, § 65. The use of nitrum in making glass is often mentioned.
1221
Plin. xxxi. 10.
1222
Lib. xxx. 10.
1223
Forskäl Flora, p. xlvi.
1224
Plutarchi Sympos. lib. vi. at the end.
1225
Theophrasti Histor. Plant. ii. 5. – Geopon. ii. 35, 2; and ii. 41. – Palladius, xii. tit. i. 3, p. 996.
1226
Virg. Georg. i. 193. – Plin. xviii. 7. 845. – Geopon. ii. 36, p. 184.
1227
Columella, ii. 10, 11.
1228
Plin. xix. 8, § 41. – Pallad. iii. 24, 6. – Geopon. xii. 17, 1. – Theophrast. de Causa Plant. vi. 14.
1229
Plin. xxxi. 10; and xix. 5, § 26, 10.
1230
Apicius, iii. 1, p. 70. – Martial, lib. xiii. ep. 17. – Plin. xix. 8, § 41, 3; xxx. 10. – Columella, xi. 3, 23. [Carbonate of soda, as is well known, is still frequently used for this purpose in culinary operations.]
1231
Herodot. ii. 87.
1232
Our tanners use unslaked lime for a similar purpose.
1233
Annot. to Dioscorides, v. 89, p. 951.
1234
A catalogue of such waters may be found in Baccii Liber de Thermis. Patavii, 1711, fol. v. 5, 6, 7, p. 160. [Carbonate of soda occurs for instance in the celebrated mineral waters of Seltzer and Carlsbad, and also in the volcanic springs of Iceland, especially the Geyser.]
1235