270 M. L. v. Karolyi on the Products of 



wires are bent into knots, which, as previously mentioned, serve 

 to support the cylinders and to complete the voltaic circuit. 



The weight of the gun-cotton whose gases shall fill the ex- 

 hausted mortar of 5216 cubic centims. contents so that there shall 

 be the tension above mentioned, I have empirically determined, 

 and find that it is 10 grms. The fact that 10 grms. of 

 cotton somewhat compressed occupy a space of 10*5 centimetres 

 in length and 2 centimetres in diameter, determined the internal 

 dimensions of the cylinder. The thickness of the sides of the 

 cylinder was also obtained from an empirical experiment, which 

 showed that with a thickness of 8 millims. the cylinder just ex- 

 ploded with production of flame, and that thus, in accordance 

 with the condition stated, the gun-cotton burnt away the moment 

 the cylinder burst. I must here mention a peculiar circumstance 

 which attracted my attention in determining the thickness of the 

 side of the cylinder, and which serves to characterize gun-cotton. 

 For the above investigation I successively filled with gun-cotton 

 cylinders 4, 6, and 8 millims. thick in the side and exploded 

 them in a hole. Although the cylinders of 4 and 6 millims. 

 in thickness contained comparatively a larger charge, the pieces 

 produced were considerably larger than those of the cylinders 8 

 millims. in thickness. The former were often only split length- 

 wise; their cover and bottom remained unchanged, while the 

 pieces of the cylinder of 8 millims. in thickness were scarcely 

 larger than hazel-nuts. 



The above bursting vessels might also probably be constructed 

 of glass. Very strong thick glass tubes are taken, and at each 

 end corks cemented in, one of which has been provided with a 

 galvanic conduction and the small platinum wire. The length 

 of the vessels and the thickness of their sides could then be regu- 

 lated by the quantity of gas and the desired resistance. 



The qualitative analysis of the products of the combustion of 

 gun-cotton under the circumstances described gave carbonic 

 oxide, carbonic acid, nitrogen, marsh-gas, and a trace of a sul- 

 phurous gas (probably a bisulphide of carbon compound), which, 

 from its small quantity, escaped analysis and could only be 

 detected by the smell. This probably arises from a small trace 

 of sulphuric acid adhering to the gun-cotton, which either was 

 not removed in washing, or by subsequent treatment with pot- 

 ash remained as sulphate. 



The quantitative gas-analysis was made according to the fol- 

 lowing plan : — 



Absorption Analysis. Vol. at 0° 



Volume. Pressure. Te ?P- andl metre. 

 Original volume . . . 114-78 06242 19-1 66'94 

 After absorbing CO 2 . 84-88 0*6048 20-2 47*81 



