957 
IV.—On Dynamite, in its sanitary aspect.—By Dr. Hupson, Redruth. 
Read at the Spring Meeting, May 16th, 1873. 
OR a considerable number of years, the fact has been recog- 
nized that the occupation of mining is much less satisfactory, 
from a sanitary point of view, than other forms of out-door work. 
The genuine miner has not only his fair proportion of trivial 
diseases, but, in addition, suffers from various affections of the 
respiratory organs, which almost double his mortality when 
compared with that of the non-mining population of the neigh- 
bourhood in which he resides. The causes of this excessive 
mortality were fully investigated by the Kinnaird Commission, 
some ten years ago. Briefly, they are: imperfect ventilation, 
candle-smoke, powder-smoke, and, in dry mines, dust from boring 
and the use of the pick. Year by year the system of ventilation 
has been improving ; and, I understand, it is comparatively rare 
to find a mine very deficient in that respect. At various stages, 
in the “rising of winzes,” or driving of levels, it is quite un- 
reasonable to expect the circulation of a free current of air, as 
these operations require time for their completion. The question 
then arises: can anything be done, beyond the employment of the 
fanning machine, in lessening the amount of foreign matter with 
which the stagnant air of “close ends” is charged. 
Dr. Angus Smith has studied the chemistry of the air of mines, 
and has published his results, in a most elaborate and complete 
form. He ascertained the main deleterious ingredients to be, 
organic matter, carbonic acid, and powder-smoke. The organic 
matter was attributed to decaying wood ; and the carbonic acid to 
the act of breathing, the burning of candles, and the explosion of 
gunpowder. Gunpowder contributes to the impure state of the 
air in yet another way. Among the injurious compounds resulting 
from its explosion, a prominent place must be given to sulphide 
of potassium, which is believed to have an effect on the body, 
when inhaled, similar to sulphuretted hydrogen, though acting 
very slowly. It is not usual for perfect combustion to take place ; 
