ON THE GASES EVOLVED FROM IRON FURNACES. 181 
If the solution of sal-ammoniac produced by the condensation of the am- 
monia be allowed to flow into an evaporating pan, over the surface of which 
a small part of the flame of the combustible gas is allowed to play, a conve- 
nient arrangement of the liquid and of the burning stream of gas would en- 
able us to obtain a constant flow of a concentrated solution of sal-ammoniac 
as an auxiliary in the manufacture. The advantage of its collection is, that 
without any further consumption of fuel, or any considerable expenditure of 
labour, a valuable commercial ingredient would be economised. Hence it is 
of importance to estimate how much ammonia we might hope to obtain in 
this way ; and this is easily determined by the quantity generated during the 
distillation of coal. We have subjected the furnace-coal of Alfreton to 
various trials, both by distilling it per se, and along with a mixture of soda 
and lime, and then by separating the ammonia in the usual way from the 
liquid products of distillation by means of chloride of platinum. 
I. 2°887 furnace-coal of Alfreton, heated with soda and lime, yielded 
0:0801 chloride of platinum and ammonia. 
II. The experiment repeated with 5°687 coal gave 0°175 chloride of plati- 
hum and ammonium. 
III. 20°455 grms. distilled per se, gave a product collected in muriatic acid, 
which, after separation of the tar, yielded 0°7681 chloride of platinum and 
ammonium. 
Hence 100 parts of the furnace-coal of Alfreton yields the following quan- 
tities of sal-ammoniac : — 
I. Experiment . . . 0666 
Il. ie aig «): O°739 
III. z! - + « 0:902 
Mean .... O69 
Now, as 280 ewt. of coal are consumed in the Alfreton furnace every twenty- 
four hours, it follows that more than 2 cwt. sal-ammoniac might be obtained 
from it as a subsidiary product, without increasing the cost of manufacture, or 
in the slightest degree disturbing the process of smelting. 
__ We have confined ourselves in this examination principally to the con- 
sideration of the furnace-coal of Alfreton, but we may naturally expect con« 
siderable differences as to the amount of nitrogen in other coals used in this 
and in other countries. The estimation of the nitrogen, with regard to the 
possibility of applying the ammonia generated by their distillation, thus be- 
comes a question of considerable importance. We therefore reserve for 
ourselves the prosecution of this inquiry in a succeeding paper. Before 
leaving this subject, however, we have to allude to some experiments, show- 
ing the facility of condensing the ammonia. 
As the gases from the upper parts of the furnace are saturated with aque- 
ous vapour, which condenses along with the ammonia in the lead tube with 
which they were collected, we have taken the proportion of the ammonia 
carried away in the gases, so as to compare it with that which had suffered 
condensation. For this purpose, the gases flowing through the iron and lead 
pipes, sunk from eight to ten and a half feet beneath the charging-plate, 
/ were conducted through muriatic acid for two hours seven minutes. We 
determined the volume of the gas passing through the acid by collecting it at 
- various times during the experiment in a balloon made of gold-beater’s skin, 
‘of the capacity of 380°8 cubic inches, observing the time which was re- 
‘quired to fill the balloon. The mean result, which deviated only slightly 
from the individual trials, showed that the gas required 1! 7 to fill the bal- 
