CAPTAIN NOBLE AND ME. F. A. ABEL ON FIEED GUNPOWDEE. 
53 
bable, and is confirmed by the fact that Gay-Lussac himself estimated the permanent 
gases at about 250 volumes. 
In 1825 Chevreul* * * § , after drawing attention to the difference in the decomposition 
of gunpowder when occurring explosively, as in the bore of a gun, and when taking 
place slowly, as by ignition in open air, supposes the decomposition in the former case 
to be represented by the equation 
2K N0 3 +S+C 3 =K 2 S + N 2 +3C0 2 . 
He points out that the actual constituents of gunpowder are employed in proportions 
almost in exact accordance with this formula ; and the same view appears to have been 
taken by Graham^, who further supposes that the potassium sulphide is converted into 
sulphate on coming into contact with the air. 
Chevreul gives potassium sulphide, sulphate, carbonate, cyanide, nitrate or hypo- 
nitrite, and carbon as composing the solid residue of gunpowder when burnt slowly ; and 
gives further, as the result of some experiments of his own, for the gaseous products in 
100 volumes : — 
Carbonic anhydride . . 
, . 45-41 vols. 
Nitrogen 
. . 37-1)3 ,, 
Nitrous oxide 
. . 8-10 „ 
Sulph. hydrogen . 
. . 0-59 „ 
Marsh-gas 
. . 3-50 „ 
Carbonic oxide . . . 
. . 4-87 „ 
Between the years 1831-36 a great number of very important experiments, chiefly 
upon the combustion and inflammation of gunpowder, were made by General Piobert. 
The results of these experiments, together with Piobert’s theoretical views, are contained 
in his work on the properties and effects of gunpowder J. 
Piobert considered that the velocity of inflammation of gunpowder, that is the trans- 
mission of the ignition from one grain to another, when the charge was contained in a 
close vessel or tube offering a high resistance, was very great ; but he did not§ consider 
that the influence of the high temperature and great tension of the gases exercised a 
sensible effect in increasing the rapidity of combustion of the individual grains. 
It is somewhat difficult to collect his views upon the subject of the decomposition of 
gunpowder ; and his work on this point must be taken more as a resume of the views of 
chemists on the subject than as an expression of his own. He seems, however, to have 
ascribed a great influence to the mode of ignition, even on the quantity of permanent 
gases, and quotes results varying from 200 volumes to 650 volumes. ||, all taken at atmo- 
spheric temperatures and pressure. 
* Dictionnaire des Sciences Naturelles, tom. xxxv. p. 58. 
f Encyclopaedia Britannica, Art. “ Gunpowder.” 
± Piobert, G., ‘ Traite d’Artillerie, Proprietes et Effets de la Poudre/ 1859. 
§ Loc. cit. pp. 158-162. || Loc. cit. p. 292. 
