52 Professor Boscoe [Feb. 21 » 



giving rise to the ammonia which is always contained in the atmo- 

 sphere, or by the dry distillation of the same bodies, that is, by heating 

 them strongly out of contact with air ; and it is from this source that 

 the world derives the whole of its commercial ammonia and sal- 

 ammoniac. 



Coal, the remains of an ancient vegetable world, contains about 

 2 per cent, of nitrogen, the greater part of which is obtained in the 

 form of ammonia when the coal undergoes the process of dry distilla- 

 tion. In round numbers two million tons of coal are annually dis- 

 tilled for the manufacture of coal gas in this country, and the ammo- 

 niacal water of the gasworks contains the salts of ammonium in 

 solution. 



According to the most reliable data 100 tons of coal were distilled 

 so as to yield 10,000 cubic feet of gas of specific gravity * 6, giving 

 the following products, in tons : — 



Gas. Tar. Ammonia Water. Coke. 



22-25 8-5 9-5 59 • 75 average. 



This ammonia water contains about 1 • 5 per cent, of ammonia, 

 hence the total quantity of the volatile alkali obtainable from the gas- 

 works in England amounts to some 9000 tons per annum. 



A singular difference is observed between the dry distillation of 

 altered woody fibre as we have it in coal, and woody fibre itself. In 

 the products of the first operation we chiefly find in the tar the 

 aromatic hydrocarbons, such as benzene, whilst in the second we find 

 acetic acid and methyl alcohol are predominant. 



The year 1848 is a memorable one in the annals of revolutionary 

 chemistry, for in that year Wurtz proved that ammonia is in reality 

 only one member of a very large family. By acting with caustic 

 potash on the nitriles of the alcohol radicals he obtained the first 

 series of the large class of compound ammonias, the primary mona- 

 mines. Of these methylamine is the first on our list : — 



CH3|n + 2KOH = CH3|n + co{OK 



The years that followed, 1849-51, were prolific in ammoniacal 

 discoveries. Hofmann pointed out that not only one atom of hydrogen 

 in ammonia can be replaced by its equivalent of organic radical, but 

 that two or all the three atoms of the hydrogen in ammonia can be 

 likewise replaced, giving rise to the secondary and tertiary amines, by 

 the following simple reactions : — 



HI CH3I 



1. CH3I + H N = HI+ H N 



h) H I 



CH3) CH3 



2. CH3I + H }N = HI + CH3 }N 



H J H 



CH3I CH3, 



3. CH3I + CH3 N = HI + CH3 N 



h) CH,: 



