THEORY OF FERMENTATION 337 



smaller flask had been previously filled with carbonic acid. 

 The carbonic acid of the fermented liquid was then ex- 

 pelled by means of heat, and collected over mercury. In 

 this way we found a volume of 8.322 litres (508 cubic 

 inches) of gas in solution, which, added to the 2.135 litres, 

 gave a total of 10.457 litres (638.2 cubic inches) at 20 and 

 760 mm., which, calculated to o, C. and 760 mm. atmospheric 

 pressure (32 F. and 30 inches) gave a weight of 19.700 

 grammes (302.2 grains) of carbonic acid. 



Exactly half of the lime in the tartrate employed got 

 used up in the soluble salts formed during fermentation; 

 the other half was partly precipitated in the form of car- 

 bonate of lime, partly dissolved in the liquid by the carbonic 

 acid. The soluble salts seemed to us to be a mixture or 

 combination of i equivalent of metacetate of lime, with 2 

 equivalents of the acetate, for every 10 equivalents of car- 

 bonic acid produced, the whole corresponding to the fermen- 

 tation of 3 equivalents of neutral tartrate of lime. 4 This 

 point, however, is worthy of being studied with greater care : 

 the present statement of the nature of the products formed 

 is given with all reserve. For our point, indeed, the matter 

 is of little importance, since the equation of the fermenta- 

 tion does not concern us. 



After the completion of fermentation there was not a 

 trace of tartrate of lime remaining at the bottom of the 

 vessel: it had disappeared gradually as it got broken up into 

 the different products of fermentation, and its place was 

 taken by some crystallized carbonate of lime the excess, 

 namely, which had been unable to dissolve by the action of 



uring tube. The liquid condensed by boiling forms pure water, the solvent 

 affinity of which for carbonic acid, at the temperature we employ, is well 

 known. 



4 The following is a curious consequence of these numbers and of the 

 nature of the products of this fermentation. The carbonic acid liberated 

 being auite 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 

 alts of lime, with a mass of organic matter at the bottom, without any 

 liberation of gas or appearance of fermentation ever taking place, except 

 8 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 50 grammes 

 (767 grains) of tartrate of lime. 



