370 
MINUTES OF PROCEEDINGS OF 
series, was never raised. The Eeport throughout is based on the assumption 
that identical methods of treatment must yield identical results; that no 
analysis was required: that practice in firing supplied the ultima ratio; 
and, lastly, that the results of explosion were referable to chemical composition 
wholly and absolutely. The first proposition is usually, but not invariably 
true, as every chemist knows. 
Minor circumstances frequently influence the result of chemical energy, 
though primary conditions remain unchanged. Chemists sometimes, 
heeding these primary conditions only, imagine they have continued to 
do the same thing and to achieve the same result; whereas different 
acts have been performed, and different results accomplished. This has 
happened in prosecuting the manufacture of gun cotton, up to the ex¬ 
periments of Baron Lenk. What may take place during the change of 
ordinary cotton into gun cotton, under different conditions, can be thus 
expressed. The cellulose (matter of cotton) may yield up successive 
increments of hydrogen, to be replaced by hyponitric acid, according as the 
acid bath employed varies as to relative bulk, and the time of action 
varies. One equivalent of hydrogen is removable more easily than two, two 
than three, &c. &c. 
In this way, not only may specimens of gun cotton (as commonly prepared) 
be made up of variable mechanical mixtures, of every chemical result 
possible under the circumstances, but the series may be still further extended 
by the interpolation of material upon which no chemical action has been 
exerted. Hence may be deduced a most important distinction between the 
Trench gun cotton and that of Baron Lenk. 
Difference between the French Gun Cotton and Baron LenJc’s . 
5. According to the method pursued by the French Commission, the 
raw cotton was immersed in the acid mixture for one hour. 
Baron Lenk leaves his cotton forty-eight hours in the acid bath. 
The French cotton was afterwards dipped in running water for an hour 
or an hour and a half. 
Baron Lenkas gun cotton lies four, six, or eight weeks in a stream. 
The French cotton had, after washing, so much free acid left, that wood- 
ash ley (a solution of carbonate of potash, therefore), was neutralized by 
contact with it, and after long use became sour. 
Baron Lenkas cotton is so freed from acid by long immersion, that a two 
per cent, solution of potash, in which two hundredweight of gun cotton had 
been boiled, had lost none of its alkaline properties; that is to say, that the 
cotton was completely free from acids, as experiments wholly accordant 
with those of the Imperial (Austrian) Engineers* Committee fully demon¬ 
strated. The French gun cotton having been prepared in a manner so 
different, it must necessarily have had a different composition to that of 
Baron Lenk*s; hence it is clear that the French experimental results cannot, 
without considerable reserve, be accepted as precedents. 
Lenk’s Cotton is Tri-nitro Cellulose and uniformly composed, 
6. It manifested no inconsiderable amount of confidence on the part of 
Baron Lenk, when the French experiments were known to him, that he did 
