CONDITIONS FAVOURING FERMENTATION. 



39 



formation of urea into carbonate of ammonia goes on at a very 

 appreciable rate whilst the urine is exposed in the incubator to a 

 temperature of 122^ F. (50° C). 



Experiments made with another specimen of urine of very nearly 

 the same acidity yielded the following results. Exactly one fluid- 

 ounce was used, as before, in each experiment. 



Urine whose aci- 

 dity was exactly 

 neutralized by ix 

 minims of liquor 

 potassae to the fluid 

 ounce. 



Treatment. 



1. Boiled gently for 5"over 

 flame, without spurting, 



2. Boiled for 2" over flame, 

 8" in can of water. 



3. Boiled for 2 ' 'over flame. 

 8" in can. Left at 122° F. 

 for 3 days. 



4. Boiled for 2"over flamo' 

 18" in can. 



5. Boiled for 2" over flame, 

 1^ 38" in can. 



Besult. 



1. Diminished by 5i. 

 Acidity =m. yjI of liq. pot. 



2. Diminished about 3^. 

 Acidity = m. vj of liq. pot. 



3. Diminished by 5|^. 

 Acidity =m. iv of liq. pot. 



4. Diminished by 3^. 

 Acidity =m. ivj liq. pot. 



5. Diminished by 3^. 

 Acidity =m. iij liq. pot. 



The urea in this specimen seemed to undergo change rather 

 more rapidly than in the last, as a careful comparison of the 

 figures will indicate. Experiments 2, 4, 5 also seemed to show 

 that the change takes place most rapidly at first, and subsequently 

 tends to diminish ; thus in No. 2, after ten minutes' boiling over 

 flame and in can, we get a diminution of acidity equivalent to 

 m. iij of liquor potassse ; in No. 4, with an extra 10 minutes' boil- 

 ing in the can the further diminution of acidity only equals m. i| 

 of liquor potassse ; whilst in No. 5, with a still further period of 

 20 minutes' boiling the additional diminution of acidity w^as also 

 equivalent to m. i| of liquor potassse. 



Other experiments were made to ascertain whether the change 

 of urea into carbonate of ammonia would still go on at lower tem- 

 peratures ; and this time the urine was one of much higher acidity 

 and specific gravity. Exactly one fluid-ounce was used, as before, 

 in each experiment. 



( Treatment. 



1. Boiled for 2"over flame, 

 C/riwe whose aci- 8" in can. 

 dity was exactly 2. Boiled for 2"over flame, 

 neutralized by \ g" in can. Left at 83° R 

 m. xxj of hquor po- | for 7 days. 



3. Boiled for 2"over flame, 

 8" in can. Left at 122^ R 

 ^ for 7 days. 



tassae to the fluid- 

 ounce 



Bemlfs. 



1. Acidity = m.xviij of liq. 

 pot. 



2. Acidity =m. xvj of liq. 

 pot. 



3. Acidity =m. xiij of liq. 

 pot. 



From this it appears that the diminution of acidity goes on at 



