Fermentations by Organisms 823 



Experiment CCCCXXXI. August 10. Boiled milk; placed in a layer 

 2 to 3 millimeters thick in two new, well- washed crystallizing pans: 



A, in the open air, under a glass which kept out dust; 



B, at 25 atmospheres of superoxygenated air. 

 August 14. Decompressed. 



A has been coagulated since August 11, and smells very bad. 

 B is liquid, has no odor, and seems quite normal. 



Experiment CCCCXXXII. May 25. On the bottom of 6 tubes a few 

 drops of boiled milk (depth y 2 centimeter) are carefully dropped. 



A. 2 tubes are closed with a flame and kept as controls. 



B. The other 4, drawn out in the flame but open, are subjected to 

 15 superoxygenated atmospheres in the glass cylinder. 



June 1. Decompressed. 



A has been coagulated since May 27. 



B is not coagulated; closed with the flame. 



June 6. B not yet coagulated. 



These experiments prove very clearly that oxygen under high 

 tension prevents the coagulation of milk, that is, kills the vibriones 

 which cause lactic fermentation. As the action of these vibriones 

 takes place very rapidly, to check it oxygen must be used in a 

 very high concentration upon a thin layer of liquid, which must 

 be saturated rapidly. For putrefaction, which works much more 

 slowly, these excessive precautions are not necessary; since milk 

 does not, like blood, consume the oxygen as it penetrates the liquid, 

 the oxygen has time to go to the bottom of the tubes and kill there 

 the agents of putrefaction. That explains why it is so easy by 

 compressed air to prevent milk from putrefying, and so hard to 

 prevent it from coagulating. 



3. Alteration in urine. 



Since the research of M. Van Tieghem, we know that the trans- 

 formation of urea to carbonate of ammonia is a true fermentation, 

 due to the development of a microphyte, of a torula. 



Therefore I studied it somewhat in detail. 



Experiment CCCCXXXI1I. August 8. Temperature 27°. Urine of 

 the day before, quite acid; in equal quantities in three small bottles 

 covered by paper cones, and placed: 



A, at normal pressure, under a bell; 



B, in the small Seltzer water receiver, at 4 atmospheres of air; 



C, in the cylindrical glass receiver, at 7 atmospheres of an air 

 containing 70% of oxygen, which corresponds to 24 atmospheres of air. 



August 11. A, quite turbid, foul, but still acid. 



B, decompressed; a little turbid, a little bad odor. Taken to 5 

 atmospheres of air. 



C, decompressed; no turbidness; fresh odor. Taken to 5 atmos- 

 pheres with 71% of oxygen, that is, about 18 atmospheres of air. 



