224 



Original Articles. 







Grammes. 



Grains. 



Oxygen 



9048-957 



139737-7945 



Nitrogen 



33726-7 



520470-4 



Carbonic acid 



1200-44 



18525-2 



Carbonic oxide 



3188 



49-2 



Hydrogen 



0-07186 



1-1088 



Sulph. hydrogen . 



0-59869 



9-2389 



Sulphate of potash 



144-760 



2233-936 



Carbonate of potash . 



43-311 



668375 



Hyposulphite of potassium 



11-189 



172-668 



Sulphide of potassium 



7-296 



112-592 



Sulphocyanide of do. . 



1-049 



16-186 



Nitrate of do. 



12-751 



196-773 



Carbon .... 



2-494 



38-482 



Sulphur 



0-466 



7-191 



3/2 carbonate of ammonia 



9-790 



151-079 



Organic matter . 







Sand .... 







Sulphurous acid, or 







Sulphite of ammonia . 







Arsenious acid 







[April, 



Organic arid Solid Matter.— The reason we feel ill in air having 

 only from one to two-tenths of carbonic acid, is mainly owing to the 

 organic matter by which it is accompanied. The mines contain such 

 organic matter also, and if not in the same proportion as in crowded 

 rooms, there are other substances, as we have seen, which make up for 

 it. If we are suddenly brought into a crowded room, it is very un- 

 pleasant ; but if the room is emptied, and the air has time to change, 

 it is not less unpleasant to breathe for some time, because of the 

 organic matter which has been left clinging to everything. Mine air, 

 however, is still worse ; if you take a cubic inch of it away to a spot 

 where the air is pure, and then breathe it, you will have obtained a 

 good specimen, if you do not smell grease, tobacco, and sourish per- 

 spiration, or you may perhaps consider it a little putrid. We never 

 go at once into a mine ; we can only go gradually. How dreadful to 

 be launched at once into an atmosphere, a cubic inch of which is 

 more than enough to give rise to unpleasant sensations to half-a-dozen 

 persons ! Yet such air exists in the mines. 



Smoke and Bust. — But these things are not all. There is in the 

 air a great abundance of solid substances. These are found on the 

 sides of the tubes of collected air, and were examined by the micro- 

 scope. They consist of sand and of carbon, but also of crystals of sul- 

 phate and nitrate of potash. The sulphide of potassium goes into 

 sulphate, and some of the gunpowder is not decomposed. The men 

 breathe these continually. 



Sometimes at dead ends or extremities of levels, especially when 

 there is a rise, the air is such that no man can work above ten minutes, 

 and they take it in turns. So we have been told by miners ; we have 

 not been in such places in mines, but we do not feel surprised at the 

 assertion. 



Water and Boilers. — We can ouly say a few words on boilers. 



