(3) In the carbonisation of small coal for the manu-
facture of coke for smelting purposes by the Simon-Carves,
Semet-Solvay, and other ovens, the condensed gases produce
a good return of ammonia.
BONE PRODUCTS AND MANURES 103

Westphalian coal (Germany) yields on carbonisation for
coke about fourteen per cent, of aramoniacal liquor at 4° B.,
equal to a production of 1 ton ammonium sulphate per 100
tons dry coal coked. An average English coal for coking
yields about 22 cwt. per 100 tons dry coal.
(4) Another source of ammonia is the destructive dis-
tillation of shale, as carried on by the Scotch mineral oil
companies. The yield of ammonium sulphate will range
from 16 to 18 cwt. per 100 tons shale treated.
(5) In the carbonisation of bones for the manufacture of
animal char, a further supply of ammonia is obtained. This
is treated fully under " Animal Charcoal."

Sulphate of ammonia is a chemical combination of the
gas ammonia with sulphuric acid.
2NIl3 + H2SO, = (NH,),SO,.
Ammonia + sulphuric acid = ammonium sulphate.
The product commercially has a grey colour, due to tarry
matter in a very fine state of division spread through the
mass. Two analyses by the author gave the following
results : —



Moisture.
(1)
3-51


(2)
5-72


Sulphate of ammonia




94-87


93-26


Organic matter.
-85


•54


Mineral matter


>(1)
(2)


-77


•48




100-00


100-00


E(iual to ammonia (NHg^




24-43 per cent.
24-02 „



The production of sulphate of ammonia in this country
is about 120,000 tons per annum, this amount being prac-
tically all used for agricultural purposes.
The value of sulphate of ammonia naturally depends on



104 BONE PRODUCTS AND MANURES

the nitrogen it contains and the rapid manner it diffuses
itself through and is thus absorbed by the soil.
