104 Scientific Intelligence. ° 
No. 1. This charge was about one hour after the 7th, during which pe- 
riod it had been carried, wrapped tight in paper, in my hand, while 
searching for the ball of the 7th shot. It may have absorbed moisture. 
It appears from the 4th, 5th and 7th shots, that the distance projected 
increases faster than the quantity.” 
Dr. Dana also tried the gun-cotton in blasting rocks, in the line of a 
new canal now excavating in Lowell. The first trial was on a ledge of 
argillo-micaceous slate, very hard and tough. The portion selected was 
imperfectly stratified in an almost vertical direction, with a perpendicu- 
lar face about 9 feet high. Two holes each 13 inches diameter, were 
drilled into this rock_51 and 6 feet from the face, 12 feet asunder, and 
p- *Gun-cotton (No. 4 above) was enclosed in car- 
tridges of cotton cloth, 1} inches diameter, and respectively 2 feet 10 
inches, and 5 feet long, holding 9 and 11 ounces. The holes were fill- 
ed with dry sand over the cartridges, (5 feet over one, and 6 over the 
other,) which were then fired by an attached fuse. The explosions oc- 
curred within a few seconds of each other, with a sharp but not loud 
| very little smoke. The result was highly satisfactory to the 
nd contractors under whose inspection the experiment was 
tried. The mass of rock moved was 25x5xX9 feet — 1125 cubic 
feet, or about 90 tons weight, moved by 20 ounces of gun-cotton ! 
after the method proposed, and successfully employed by Mr. A. A. 
aden Roxbury, which is substantially the same as that already 
ribed. 
_ Some experiments on the cotton-powder in mining have been made 
in Cornwall by Prof. Schénbein and Mr. R. Taylor,* and with the most 
satisfactory results. It was found practicable to enter immediately 
after explosion into a narrow adit 600 or 700 fathoms from day, where 
it would not have been possible to have entered under three quarters of 
an hour, if a like amount of common powder had been burnt there. 
_ The action of nitric acid in producinga highly inflammable substance 
is by no means confined to cotton. M. Pelouze, in 1838, observed that 
common unsized paper, after similar treatment in strong nitric acid, 
Ce. 
gd ulose, starch, 
or clean cotton fibre, may be expressed by the formula C,. F 10 Pr0* 
yloidine may then be considered as cellulose, in which a part of the 
hydrogen is replaced by nitrous acid. Substitutions of this sort have 
eatin 
* Chemical Gazette, London, Nov. 1, 1846, 
