300 ME. ABEL'S EESEAECHES ON GUN-COTTON. 



Experiment 1 shows that a repeated immersion of the gun-cotton in a fresh mixture 

 of the acids raised the weight of 100 parts of cotton to 182"13, a number somewhat 

 higher than that obtained by Hadow ; but that, by protracting the treatment beyond 

 the point when the product ceased to increase in weight, a slight but continuous loss 

 was sustained, which, there appears no doubt, from the results of confirmatory experi- 

 ments, is to be ascribed to the solution of small quantities of gun-cotton in the strong 

 acids with which it was left in prolonged contact. 



The following results show that the repeated immersion of cotton in an acid-mixture 

 of somewhat less strength, does not effect, nearly as rapidly or as completely, its conver- 

 sion into insoluble gun-c(»tton, as does a single treatment with the acid-mixture pre- 

 scribed by Von Lenk. 



{Experiment 10.) — 2-12 grms. of pure dry cotton were submitted to two successive 

 treatments with a cold mixture of acids having the composition 



HNO.,] 



HgS 



O4/ 



+ .SH2O*. 



Period of first immersion three hours, increase in weight . . 62-34 per cent. 

 Period of second immersion nine hours, increase in weight . 65-14 per cent. 



The product was then digested for three hours in the cold with the strongest acid- 

 mixture, after which the total increase in weight was 7 7 '51 per cent. 



Experiments 2, 3, and 4 prove that, by a single treatment of cotton with a consider- 

 able proportion of the strongest acid-mixture, results may be obtained closely in accord- 

 ance with the number given by Hadow, and with the theoretical requirement of trinitro- 

 cellulose. The mean of these three experiments fixes the maximum increase in weight 

 which cotton is capable of attaining by this treatment at 82'16 per cent. ; the theoretical 

 number is 83-3 per cent. 



Experiments 5, 6, and 7 show that, even in operating upon small quantities of com- 

 paratively very pure cotton, if the proportions of the acid-mixture used be limited to 

 such as are employed in manufacturing operations (10 to 14 parts to 1 of cotton), the 

 conversion into trinitro-cellulose cannot be as completely accomplished. In these 

 instances, the increase of weight sustained by the cotton is between 78 and 80 per cent. 

 As might have been anticipated, the products contained notable proportions of matter 

 soluble in ether and alcohol, while those obtained in experiments 2, 3, and 4 yielded a 

 minute trace to the solvent. 



Experiment 8 demonstrates the importance of continuing the digestion with acids 

 longer than is merely necessary for the production of an explosive material, if it is 

 desired to effect as complete a conversion as possible into insoluble gun-cotton. By 

 immersion for ten minutes only, the cotton increased in weight only 62-43 per cent., 



* This is the composition of the mixture which Hadow believes to bo the weakest which is capable of pro- 

 ducing insoluble gun-cotton by repeated immersions. The nearest expression of the composition of Yon Lenk's 



. rlOHNO, 

 aeid-mixtm-eis|^gjj^gQ^. 



