ODOROUS PErNCTPLES. 67 



tion of certain parts, as the axilla and sometimes the feet, has 

 a distinct odor. This is supposed to be due to combinations 

 of volatile fatty acids with soda and potassa. Most of the 

 inferior animals have a distinctive odor, which may generally 

 be readily recognized, and is always strongly developed in 

 the blood by the addition of sulphuric acid. Barreul gives 

 the following conclusions as the result of an extended series 

 of observations on this subject : 



" 1. That the blood of every species of animal contains 

 a principle peculiar to each one. 2. This principle, which 

 is very volatile, has an odor like that of the perspiration. 



3. The volatile principle is in a state of combination in the 

 blood, and while this combination exists it is not appreciable. 



4. When this combination is destroyed, the principle of the 

 blood becomes volatile, and from that time it is not only 

 possible, but very easy to recognize the animal to which it 

 belongs. 5. In each species of animal the odorous principle 

 is manifested with greater intensity in the male than in the 

 female. 6. The combination of this odorous principle is in 

 a state of solution in the blood which permits it to be devel- 

 oped either in the blood entire, in the defibrinated blood, or 

 in the serum. Y. Of all the means employed for setting free 

 the odorous principle of the blood, concentrated sulphuric 

 acid is that which succeeds the best. It suffices to add one- 

 third or one-half of the volume of blood employed, and a few 

 drops of blood is sufficient." 1 



Lactic Acid Pneumic Acid Pneumate of Soda. 



Lactic acid may be formed by what is called the lactic acid 

 fermentation of sugars, particularly sugar of milk. This kind 

 of action is induced by the presence of certain organic fer- 

 ments, or by organic iiitrogenized matter in process of de- 

 composition. This principle does not exist, as was at one 



1 ROBIN and VERDIEL, op. dt., tome Hi., p. 90. 



