Col. Gibbs on Gunpowder; 87 
Anr. XIX. On a Method of Augmenting the Forte of Gun- 
powder. 
Extract of a Letter to the Editor, from Col. Gzorcr Ginrs. 
I EMPLOYED, the last year, a man in blowing rocks, and 
having seen an account of a method of substituting a portion of 
quick lime for a part of the gunpowder usually employed, I was 
induced to make a number of experiments upon it. I now 
send you the results, in the certificate of the person employed, 
whose statement might be relied on, even if I had not super- 
intended myself a number of the experiments. = 
“ Sunswick Farms, Oct. 19, 1817.—I certify that, having been 
employed by Colonel Gibbs in blasting: rocks on his farm, I, by 
his orders, made use of a composition of one part quick lime 
and two parts gunpowder, and uniformly found the same charge 
to answer equally well with a like quantity of gunpowder. I 
made upwards of fifty blasts in this manner, as well as several 
hundreds in the usual way, and can therefore depend upén the 
accuracy of this statement. I found, however, that when the 
powdered lime was mixed with the gunpowder the day before, 
the effect was diminished. It should be always used the day 
it is mixed, 
- (Signed) T. Pomzroy.” 
This preparation was made generally in the morning, put into 
a bottle and well corked, to prevent the access of the external 
ar. The rationale of the process was not explained in the 
Sriginal recommendation, but it soon occurred to me, that it 
en be owing to the desiccation of the gunpowder by the 
ime. 
The attraction of moisture by gunpowder, is known to be 
very great : according to Rees’s Cyclopedia, upwards ‘a “ 
Per cent. has been absorbed, and that the removal, simply, 
