582 



Adenky — Dissolved Gases and Fermentative Changes. 



course, be accounted for by the results recorded in the Table, and therefore the 

 objection that the volume of oxj^gen given as absorbed during fermentation is 

 probably too low. 



I feel confident, however, from experiments which have, from time to time, 

 been made in the course of my work, and which have given me the means of 

 estimating the error attending the ojjeration here described, with a liquid 

 containing so much dissolved oxygen as this one did at the time of re-bottling, 

 that the error certainly does not exceed 0'5 c.c. 



It has already been pointed out, when discussing the results of the experiments 

 with the filtered sewage-water, recorded in Table V., that the second-stage 

 fermentation was accompanied by the formation of a decided quantity of carbon 

 dioxide. It therefore appears from this that filtration affects the earlier steps of 

 the first stage in much the same way that dilution does. 



It is of importance to note in relation to the objects which I have had in view 

 in the carrying out of this investigation, that, notwithstanding the variations in 

 the chemical changes which these experiments with the solution of asparagine and 

 tartrate have shown to be possible during the intermediate steps of fermentation, 

 according as the quantities of fermentable organic matters and of atmospheric 

 oxygen are varied, relatively to one another, the total quantities of carbon 

 dioxide formed, and of oxj'gen absorbed, during the whole course of fermenta- 

 tion may, for practical purposes, be taken as independent of such variations, 

 provided that aerobic conditions be maintained throughout the complete course 

 of fermentation. 



This will be readily seen when the products of the complete fermentation in 

 each dilute solution are multiplied so as to render them comparable with those 

 obtained from the undiluted solution A, thus : — 



We find from the above Table that the total volumes of carbon dioxide evolved 

 during the whole course of fermentation in the dilute solutions, when multiplied 



