The following is a curious consequence of these numbers and of the nature of the products of this fermentation. The carbonic acid liberated being quite pure, especially when the liquid has been boiled to expel all air from the flask, and capable of perfect solution, it follows that, the volume of liquid being sufficient and the weight of tartrate suitably chosen—we may set aside tartrate of lime in an insoluble, crystalline powder, along with phosphates at the bottom of a closed vessel full of water, and find soon afterwards in their place carbonate of lime, and, in the liquid, soluble salts of lime, with a mass of organic matter at the bottom, without any liberation of gas or appearance of fermentation ever taking place, except as far as the vital action and transformation in the tartrate are concerned. It is easy to calculate that a vessel or flask of five litres (rather more than a gallon) would be large enough for the accomplishment of this remarkable and singularly quiet transformation, in the case of fifty grammes (767 grains) of tartrate of lime. Footnote 139: We treated the whole deposit with dilute hydrochloric acid, which dissolved the carbonate of lime, and the insoluble phosphates of calcium and magnesium; afterwards filtering the liquid through a weighed filter paper. Dried at 100° C. (212° F.), the weight of organic matter thus obtained was 0·54 gramme (8·3 grains), which was rather more than 1/200th of the weight of fermentable matter. Footnote 140: Should the solution of lactate of lime be turbid, it may be clarified by filtration, after previously adding a small quantity of phosphate of ammonia, which throws down phosphate of lime. It is only after this process of clarification and filtration that the phosphates of the formula are added. The solution soon becomes turbid, if left in contact with air, in consequence of the spontaneous formation of bacteria. Footnote 141: The naturalist Cohn, of Breslau, who published an excellent work on bacteria in 1872, described, after Mayer, the composition of a liquid peculiarly adapted to the propagation of these organisms, which it would be well to compare for its utility in studies of this kind with our solution of lactate and phosphates. The following is Cohn’s formula:— Distilled water 20 c.c. (0·7 fl. oz.) Phosphate of 0·1 gramme (1·5 grains). potassium Sulphate of 0·1 gramme (1·5 grains). magnesium Tribasic phosphate 0·01 gramme (0·15 grain). of lime Tartrate of ammonia 0·2 gramme (3 grains). This liquid, the author says, has a feeble acid reaction and forms a perfectly clear solution. Footnote 142: On the rapid absorption of oxygen by bacteria, see also our _Mémoire_ of 1872, _sur les Générations dites Spontanées_, especially the note on page 78.