THE CHEMISTRY OF THE ANIMAL BODY. 985 



Ethylamine, C 2 H 5 NH 2 , when fed as carbonate appears in part as ethylated urea in the 



urine. l 



Trimethylamine, N(CH 3 ) 3 . Like ethylamine, this is found in herring-brine and 

 ;among the products of proteid putrefaction and distillation. In the putrefaction of meat 

 .the first ptomaine appearing is cholin, which certainly is derived from lecithin ; the cholin 

 (see p. 986) gradually disappears, and in its place trimethylamine may be detected. 3 



COMPOUNDS WITH CYANOGEN. 



The radicle NC forms a series of bodies not unlike the halogen com- 

 pounds. Owing to the mobility of the cyanogen group, Pfliiger 3 has sought 

 to attribute the properties of living proteid to its presence in the molecule, 

 whereas in the dead proteid of the blood-plasma, for example, he imagines that 

 the nitrogen is contained in an amido- group. When the cyanogen radical 

 occurs in a compound in the form of NzzC the body is called a nitril, when 



in the form of C=iN an iso-nitril. 



Cyanogen Gas, NC CN. A very poisonous gas. 



Hydrocyanic Acid, HCN. This is likewise a strong poison. Amygdalin is a glucoside 

 occurring in cherry-pits, in bitter almonds, etc. , together with a ferment called emulsin, 

 which latter has the power of transforming amygdalin into dextrose, benzaldehyde, and hydro- 

 cyanic acid. Hydrocyanic acid, therefore, gives its taste to oil of bitter almonds, and it 

 may likewise be detected in cherry brandy. 



Potassium Cyanide, KCN. This and all other soluble cyanides are fatal poisons. 



Acetonitril, or Methyl Cyanide, CH 3 CN. This and its higher homologous nitrils 

 are violent poisons. After feeding acetonitril in small doses, formic acid (see p. 978) and 

 thiocyanic acid (see below) appear in the urine, the thiocyanic acid being a synthetic prod- 

 uct of the ingested cyanogen radical, and the HS group of decomposing proteid.* After 

 feeding higher homologues of acetonitril or hydrocyanic acid, thiocyanide likewise appears 

 in the urine. Since the amount of thiocyanide in the urine is normally very small, there 

 is no reason for believing that cyanogen radicals similar to those described above are ever, 

 to any great extent, cleavage-products of proteid. 5 Through intravenous injections of 

 sodium sulphide, and especially of sodium thiosulphate, poisonous cyanogen compounds 

 may be administered much beyond the dose ordinarily fatal : 6 



NaCN + S0 2 < ^ a a + = NCSNa + Na,S0 4 . 



Cyanamide, NC.NH 2 . This is a laboratory decomposition-product of creatin, but does 

 not occur in the body. It is poisonous when administered. When boiled with dilute 

 sulphuric or nitric acids it is converted into urea : 



NCNH 2 + H 2 = H 2 NCONH 2 . 

 It is to be remembered that creatin in the body is not converted into urea. 



Ammonium Cyanate, OCN(NH 4 ). Boiling ammonium cyanate converts it into 

 urea. This was shown by Wbhler in 1828, and was the first authoritative laboratory 

 production of a body characteristic of living organisms : 



OCN(NH 4 )=OC(NH 2 ) 2 . 



This reaction illustrates Pfliiger' s idea of the transformation of the cyanogen radical in 

 living proteid into the amido- compound in the dead substance. According to Hoppe- 



1 Schmiedeberg : Archiv fur exper. Pathologic und Pharmakologie, 1877, Bd. 8, p. 5. 



2 Brieger : Abstract in Jahresbericht uber Thierchemie, 1885, p. 101. 



3 Pfliiger' s Archiv, 1875, Bd. 10, p. 251. 



4 Lang : Archiv fur exper. Pathologic und Pharmakologie, 1894, Bd. 34, p. 247. 



5 Op. cit., p. 256. 



6 Lang : Archiv fur exper. Pathologic und Pharmakologie, 1895, Bd. 36, p. 75. 



