12 DE. BASTIAN ON THE 



four days ; and when these vessels were opened their fluids were 

 also found to contain a sparing number of active Bacilli of dif- 

 ferent lengths. 



In two other experiments, in which the urine was slightly more 

 acid, requiring 9 minims of liquor potassse to the fluid-ounce for 

 neutralization, a deposit formed more slowly and was smaller in 

 amount. It was ascertained to consist principally of abortive 

 crystalline matter ; and the Bacilli, though present, were scarcer 

 still — ^not more than one or two being seen in each field of a No. 9 

 " immersion " object-glass of Nachet, with a No. 3 eyepiece. 



Finally, in two experiments with a urine. of extremely high 

 acidity (represented by 20 minims of liquor potassge to the ounce) 

 and a specific gravity of 1026, there was no appreciable naked- 

 eye change after eight days, other than the presence of a very 

 slight amount of sediment in each. On subsequently opening 

 the retorts, no organisms were found in their respective fluids, and 

 the scanty sediment was ascertained to consist of more or less 

 abortive crystals together with amorphous mineral matter. 



A few other experiments in which the liberated oxygen was 

 brought into play almost simultaneously with liquor potassse, will 

 be subsequently referred to (p. 25). 



IV. Liquor PotasscB as a Promoter of Fermentation. 



It has been well known for some time that the presence of 

 alkalies, and especially potash, favours the occurrence of fermen- 

 tation or putrefaction in suitable media. Grerhardt, for instance, 

 in his ' Chimie Organique,' said*, " Many bodies which, alone or 

 in the moist state, do not oxidize on exposure to air, undergo com- 

 bustion as soon as they are subjected to the influence of an alkali. 

 Thus pure alcohol can be kept exposed to the air indefinitely 

 without becoming acid ; but when it is mixed with a little potash, 

 it quickly absorbs oxygen and becomes converted into vinegar and 

 a brown resinous matter. It is clear from this that potash ought 

 to favour certain fermentations." A little further onf, the same 

 eminent chemist thus gives expression to a more familiar, though 

 related, fact : — "It is known that meats and vegetable substances 

 pickled in vinegar are preserved from decomposition at least 



for a certain time The majority of acids produce the 



same eff'ect as vinegar." 



The action of alkalies and of acids in favouring and retarding 

 * Tome iv. 1856, p. 547. t Loc cif. p. 556. 



