978 AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



given off on fusing proteid with potash. 1 Methyl mercaptan boils at 5, 

 and has a strong odor. It is found in the urine, especially after eating 

 asparagus, giving to it a peculiar smell. 2 According to Rubner 3 the smell of 

 cooked cabbage, cauliflower, and the like, is due to methyl mercaptan. 



Methyl Telluride, (CH 3 ) 2 Te. A gas of penetrating odor found in all excreta of an 

 animal after feeding salts of telluric, H 2 Te0 4 , or tellurious, H 2 Te0 3 , acid. The salt is re- 

 duced to metallic tellurium in the body, which unites with a methyl group in some way 

 liberated in the cells. 4 Metallic tellurium may be microscopically seen deposited in various 

 cells, and the odor of (CH 3 ) 2 Te may be detected for months after the last dose has been 

 given to a dog. 5 



Methyl Selenide, (CH 3 ) 2 Se. This is very similar to the last-named substance, but 

 more poisonous. 



Formic Acid, HCOOH. Found in ants, and obtained by distilling them 

 with water. Present likewise in stinging-nettles and in the sting of honey- 

 bees, wasps, and hornets. Its salts are found in minute quantities in normal 

 urine, and are present especially in both blood and urine in such diseases as 

 include an abnormal proteid decomposition such as Ieucocytha3mia, fever, 

 diabetes. 6 Formic acid may be obtained from the oxidation of methyl alcohol, 

 of sugar, and of starch, but not from the latter two in the body. Likewise 

 by heating oxalic acid, 



COOH 

 COOH 



= HCOOH -f CO 2 . 



It is found in the urine after feeding methyl alcohol and other methyl deriv- 

 atives, such as oxymethyl-sulfonic acid, or formic aldehyde. Ethyl alcohol, on 

 the contrary, does not yield it. 7 It is the lowest member of the fatty-acid series, 

 the most volatile, and the least readily oxidized in the body. If formates be 

 fed they appear readily in the urine. It has a penetrating odor, acts as a 

 reducing agent (HCOOH -f O = CO 2 + H 2 O), and therefore precipitates 

 Fehling's solution. Outside of the body it readily undergoes oxidation to 

 water and carbonic acid. It produces inflammation of the skin. A 7 per 

 cent, solution given to a rabbit per os has a most powerful corrosive action and 

 results fatally, formic acid being found in the urine. 



ETHYL COMPOUNDS. 



Ethyl Hydroxide, or Ethyl Alcohol, C 2 H 5 OH. This has been detected 

 in minute quantity in the normal muscle of rabbits, horses, and cattle. 8 It is 

 formed by the fermentation of dextrose, the process taking place in the yeast- 

 cell itself, alcohol and carbonic acid being the chief excretory products ; like- 

 wise, to a very small extent, the higher alcohols, propyl, isobutyl, amyl, the 



1 M. Kubner : Archiv fur Hygiene, 1893. 2 Nencki, loc. cit. 3 Loc. cit. 



4 Hofmeister : Archiv filr exper. Pathologic und Pharmakologie, 1894, Bd. 33, p. 198. 

 6 Beyer: Archiv filr Physiologic, Jahrgang 1895, p. 225. 



6 See R. Jaksch : Zeitschrift fur physiologische Chemie, 1886, Bd. 10, p. 537. 



7 Pohl : Archiv fur exper. Physiologic und Pharmakologie, 1893, Bd. 31, p. 298. 



8 Rajewsky: Pfluger's Archiv, 1875, Bd. 11, p. 122. 



