490 MM. Bunsen and SchischkofT's Chemical 



be forraed instead of carbonic acid and nitrogen. And since, 

 with the exception of unimportant traces of hydrogen and sul- 

 phuretted hydrogen, carbonic acid, carbonic oxide, nitrogen, and 

 nitric oxide alone occur in the gases from powder, 331 cubic 

 centims. must be considered to be the greatest volume of gas 

 which can in any case be formed from 1 grm. of powder of 

 the normal composition. But the experiments of Gay-Lussac, 

 and of most of the recent observers, give for powder exploded at 

 the ordinary pressure, a much larger volume than could, in any 

 case, have been obtained in accordance with these considerations. 

 From this contradiction alone, we see how uncertain and faulty 

 the methods and observations must have been which form the 

 basis of most of the preceding investigations on this subject. 



We have therefore endeavoured to obtain, in a manner less 

 uncertain thau that hitherto followed, an experimental founda- 

 tion for a chemical theory of gunpowder. 



The questions which presented themselves were the following: 



1. "What is the composition of the solid residue remaining 

 after the explosion of powder ? 



2. Of what does the smoke consist ? 



3. "What is the composition of the gases formed in the explo- 

 sion of powder ? 



4. How much residue and smoke on the one hand, and how 

 much gas on the other, are formed by a given quantity of powder? 



5. How great is the heat of combustion of powder, and how 

 high the temperature of its flame ? 



G. How great is the pressure of the gases if the powder ex- 

 plodes in the space which it occupies in the granular condition, 

 assuming that no heat is lost by radiation or by conduction ? 



7. "What is the theoretical work which the powder is capable 

 of accomplishing ? 



Unfortunately the brief time which was appropriated to our 

 researches, has not allowed us to consider these questions for more 

 than one kind of powder, and only for the combustion under the 

 ordinary atmospheric pressure. We therefore offer the following 

 experiments, not as a complete work, but rather as an example 

 to illustrate the methods followed by us, which may be used, 

 with small alterations, for the investigation of combustions of 

 powder under other conditions than those which we have 

 chosen. 



The composition of the sporting and rifle powder which was 

 used in all our experiments is obtained from the following de- 

 terminations : — 



1-2580 grm. gave 0"9960 grm. nitre. 



0-8897 grm. gave 0-7040 grm. nitre. 



0-9783 grm. gave 02054 grm. of a residue insoluble in water, 



