MR. ABEL'S BESEAECHES ON GUN-COTTON. 



The proportion of nitrogen furnished by the first experiment, though somewhat low, 

 is nearer to the requirements of the trinitro-cellulose formula than to those of the for- 

 mula adopted by PfiLOUZE and Maury ; the proportions of the gases observed in the 

 other three experiments, which happen to be identical in their results, correspond with 

 the requirements of Cg H^ N3 Gu as closely as could possibly be expected when opera- 

 ting upon a substance of approximate purity only. 



Upon calculating the proportion which the nitrogen found in these experiments bears 

 to the mean percentage of carbon (24*6) obtained by the most trustworthy method 

 employed for the determination of that element, the following numbers are obtained : — 



I. II., III., & IV. 



Carbon .... 24-6 24-6 



Nitrogen .... 13-32 13-59 



These percentage-proportions of nitrogen are not only in perfect accordance with a 

 considerable number of the results obtained by direct determination of the volume of 

 nitrogen furnished by samples of Waltham Abbey gun-cotton, they are also as close 

 approximations to the theoretical percentage of nitrogen in trinitro-cellulose as the 

 analysis of products containing small proportions of lower nitro-compounds could be 

 expected to furnish ; and lastly, the increase in weight which cotton of average purity 

 should sustain by conversion into nitro-cellulose-products which furnish these propor- 

 tions of nitrogen, corresponds closely to the average results obtained by operating upon 

 moderately pure cotton with the mixed acids of prescribed strem/th and in the propor- 

 tion (about 10 parts to 1 of cotton) indicated by Von Lenk. 



The general conclusions to be deduced from the experimental results described in 

 this memoir are as follows : — 



1. The products obtained by submitting cotton-wool to treatment with the prescribed 

 mixture of nitric and sulphuric acids, and to purification as directed by Von Lenk, are 

 very uniform in character ; they consist almost entirely of the most explosive known 

 variety of gun-cotton or pyroxylin, which is insoluble in mixtures of ether and alcohol. 

 This substance, when produced upon a manufactming scale, contains from 1 to 2 per 

 cent, of mineral substances, and a small proportion, varying with the quality of the 

 cotton, of matters soluble in alcohol, partaking of acid properties, and consisting chiefly, 

 if not entirely, of products of the action of nitric acid upon resinous or other bodies 

 enclosed in the cotton fibre. There is also always present in the gun-cotton a small 

 quantity (from 1 to 3 per cent.) of cellulose-products of a less explosive character, soluble 

 in mixtures of ether and alcohol, which result from the incomplete action of nitric acid 

 upon small portions of the cotton operated upon. 



2. The gun-cotton, when purified as far as it is possible from foreign substances, 

 soluble in alcohol and in ether and alcohol, furnishes analytical results which agree 

 much more closely with those demanded by the formula 



GfiHyNaG,,, or GgH^G^, SNG^, 



