SUBSTITUTION PRODUCTS OF THE HYDROCARBONS 23 



/CH3 

 /CH3 / /H 



N^H + HCl -> Nf-H 



Methyl amine Methyl ammonium chloride 



On decomposition the amines yield their nitrogen as ammonia, 

 and it is their ammonia relationship which connects them with 

 agriculture. The most complex nitrogen compounds of the 

 animal body, the proteins, are unquestionably amino com- 

 pounds, and on breaking down they yield simpler amino com- 

 pounds, one of these being urea, and these in turn yield the 

 nitrogen finally as ammonia, in which form it begins its con- 

 nection with plant life as plant food in the soil. These complex 

 amino compounds will be considered later. 



Cyan- amide. — One amino compound should now be con- 

 sidered in more detail. We have just discussed first the cyanides 

 and then the amines. A compound is known in which this 

 cyanide radical is substituted in ammonia just as, in methyl 

 amine, methyl is substituted in ammonia. 



H^H <r- N^H -> N^H or NC - NH2 

 \CH3 \H \CN 



Methyl amine Ammonia Cyanamide 



The compound is known as cyan-amide. It forms salts with 

 metals such as silver and calcium in which the metal replaces 

 an equivalent amount of hydrogen of the amino group. 



/H /Ag ^Ca 



N^H N^Ag m orNC-N=Ca 



\CN \CN ^CN 



Cyanamide Silver Calcium 



cyanamide cyanamide 



Calcium Cyanamide. — This calcium salt or calcium cyana- 

 mide is a new and, without doubt, a very important nitrogen 

 fertilizer. Its value to plants is due to its ammonia character, 

 as the nitrogen in this new compound in which no hydrogen is 



