198 



Capt. Noble and F. A. Abel. [Mar. 4 f 



Spiller, John, F.C.S. 

 Thudichum, John Lonis William, 



M.D., F.R.C.P. 

 Tilden, William A., D.Sc. 

 Tribe, Alfred, F.C.S. 

 Walsingham, Thomas, Lord. 



Ward, James Clifton, F.G.S. 

 Watson, Rev. Henry William, MA. 

 Wilson, Sir Samuel. 

 Wright, Charles R. Alder, D.Sc. 

 Wright, Edward Perceval, MA.,. 

 M.D., F.L.S. 



The following Papers were read : — 



I. " Fired Gunpowder. Note on the Existence of Potassium 

 Hyposulphite in the Solid Residue of Fired Gunpowder." 

 By Captain Noble (late R.A,), F.R.S., &c, and F. A. Abel, 

 C.B., F.R.S., V.P.C.S. Received February 24, 1880. 



In our second memoir on fired gunpowder we have discussed in 

 detail that part of M. Berthelot's friendly criticism of our first 

 memoir which relates to the potassium hyposulphite found by us, in 

 variable proportions, in our analyses of the solid products obtained by 

 the explosion of gunpowder in the manner described. While pointing 

 out that we had taken every precaution in our power to guard against 

 the production of hyposulphite, by atmospheric action upon the po- 

 tassium sulphide, during the removal of the hard masses of solid pro- 

 ducts from the explosion vessel, and had effectually excluded air from 

 them, when once they were removed until they were submitted to 

 analysis, we admitted the impossibility of guarding against the acci- 

 dental formation of some hyposulphite during the process of removal,, 

 especially in some instances in which the structure of the residue had 

 certainly been favourable to atmospheric action, and in which a more 

 or less considerable development of heat had afforded indications of the 

 occurrence of oxidation. 



We contended, however, that the method of analysis, and the pre- 

 cautions adopted by us in carrying it out, precluded the possibility of 

 accidental formation of hyposulphite at this stage of our investigations.. 

 With respect to the precautions, we could, and still do, speak with 

 perfect confidence ; and we certainly have believed ourselves fully 

 justified in being equally confident with respect to the process adopted 

 by us for the determination of the proportions of sulphide and hypo- 

 sulphite, inasmuch as we accepted and used in its integrity the method 

 published in 1857 by Bunsen and Schischkoff in their classical memoir 

 on the products of explosion of gunpowder, and adopted since that 

 time by several other investigators who have made the explosion of 

 gunpowder the subject of study, and whose results are referred to in 

 our first memoir. 



Imposing implicit confidence in the trustworthiness of this method 



