The modes of origin of lowest organisms

74

Loc. cit. p. 71.

75

Loc. cit. pp. 75 and 76.

76

Loc. cit. pp. 83 and 84.

77

The subsidence of the atmospheric particles has been ably demonstrated by Professor Tyndall. – See ‘Nature,’ 1870.

78

See M. Pouchet’s ‘Nouvelles Expériences sur la Génération Spontanée,’ &c., p. 69.

79

See various communications in ‘Compt. Rend.’ (1863), t. LVII.

80

Loc. cit., p. 40.

81

Speaking of experiments in closed flasks, in which the air has been either calcined or filtered, Gerhardt (‘Chimie Organique,’ t. IV. p. 545) says: – “Si dans les premières expériences l’air calciné ou tamisé s’est montré beaucoup moins actif que l’air non soumis à ce traitement, c’est que la chaleur rouge ou le tamisage enlève à l’air non seulement les germes des infusoires et des moisissures, mais encore les débris des matières en décomposition qui y sont suspendues, c’est-à-dire les ferments dont l’activité viendrait s’ajouter à celle de l’oxygène de l’air.”

82

On what other supposition can one explain the results of experiments LVII.–LXV., and of others alluded to on p. 100 (#Page_100)?

83

See notes on pp. 73 (#Page_73) and 79 (#Page_79). It was not that these fluids were incapable of being inoculated, or that they were unsuitable for the development of the lower forms of life, as was shown by their subsequent fate, and by the fact that they can always speedily be made to become turbid if they are really inoculated with living Bacteria. Almost similar facts in opposition to the prevalent Panspermic views have been noted by Professor Cantoni (Rend. del R. Istit. Lombardo, Novembre, 1869). He found (as I have also frequently found) that when fluids had been subjected to the influence of high temperatures, and had subsequently remained sterile in closed flasks, they might be freely exposed to the air for one or two weeks, or more, without becoming turbid – although at any time a general turbidity could be speedily induced, by introducing a few living Bacteria into the fluid.

84

‘On the Direct Correlation of Mechanical and Chemical Forces.’ – Proceedings of the Royal Society, vol. xii. pp. 539 and 546.

85

‘Traité de Physiologie.’ Translated by Jourdan. 1837. t. i., p. 18.

86

‘American Journal of Science,’ July, 1862.

87

See Gerhardt’s, ‘Chimie Organique,’ t. iv. pp. 540 and 547.

88

It was, indeed, the consideration of these latter facts which originally forced Gay-Lussac to the conclusion, that fermentation would not take place in vacuo, or without the presence of free oxygen, which was and still is, believed by many, to be the immediate determining cause of fermentation.

89

This proof is more severe in certain other experiments (not yet published) in which I had the benefit of Professor Frankland’s assistance. The vacuum in these cases was perhaps more perfect, having been procured by means of a Sprengel’s pump and a simultaneous ebullition of the fluid, during which the flasks were hermetically sealed. The closed flasks were subsequently exposed to a temperature of 293° F. for a short time.

90

An examination of tins of “perfectly good” meats has convinced me that a very small number of Bacteria and Leptothrix filaments are occasionally to be met with.

91

It has, however, been ascertained by M. Pouchet, that beer-yeast, even after prolonged ebullition, will undergo change in a flask which is full and hermetically sealed; and the manufacturers of preserved meats also find that occasionally, in some of their best prepared tins, the meats become putrid, and that the putridity is accompanied by the presence of organisms. Some fermentations are doubtless attended by a less copious emission of waste gases than that which characterizes other fermentations; and some fermentations will progress in spite of a moderate amount of pressure.