Intelligence and Miscellaneous Articles. 385 



"«a 



the synthetic proportions originally mixed. The residuum of char- 

 coal and sulphur left on the double filter-paper being well dried by the 

 heat of ordinary steam, is estimated as usual by the difference of 

 weight of the inner and outer papers. This residuum is cleared off 

 into a platina capsule with a tooth-brush, and digested in a dilute so- 

 lution of potash at a boiling temperature. Three parts of potash are 

 fully sufficient to dissolve out one of sulphur. When the above solu- 

 tion is thrown on a filter, and washed first with a very dilute solution 

 of potash boiling hot, then with boiling water, and afterwards dried, 

 the carbon will remain ; the weight of which deducted from that of the 

 mixed powder will show the amount of sulphur." 



Dr. Ure says that he has tried other and more direct modes of es- 

 timating the sulphur, but with little satisfaction ; such as dissolving it 

 by means of hot oil of turpentine, its conversion into sulphuric acid 

 by the use of nitric acid and chlorine, &c. 



" If we inquire," says Dr. Ure, " how the maximum gaseous volume 

 is to be produced from the chemical reaction of the elements of nitre 

 on charcoal and sulphur, we shall find it to be by the generation of 

 carbonic oxide and sulphurous acid, with the disengagement of nitro- 

 gen. This will lead us to the following proportions of these consti- 

 tuents : — 



1 prime equivalent of nitre 102 75*00 per cent. 



1 do. do. sulphur.... 16 11-77 



3 do. do. charcoal .. 18 13-23 



136 100-00 

 The [acid of the] nitre contains five primes of oxygen, of which 

 three, combining with the three of charcoal, will furnish three of car- 

 bonic acid gas, while the remaining two will convert the one prime of 

 sulphur into sulphurous acid gas. The single prime of nitrogen is, 

 therefore, in this view disengaged alone. 



The gaseous volume, on this supposition, evolved from 136 grains 

 of gunpowder, equivalent in bulk to 75 grains of water, or three-tenths 

 of a cubic inch, will be, at the atmospheric temperature, as follows : 



Grains. Cubic Inches. 



Carbonic oxide 42 = 141-6 



Sulphurous acid 32 = 47*2 



Nitrogen 14 = 47°4 



being an expansion of one volume into 787*3. But as the temperature 

 of the gases at the instant of their combustive formation must be in- 

 candescent, this volume may be safely estimated at three times the 

 above amount, or considerably upwards of two thousand times the 

 bulk of the explosive solid." — Ibid. 



PURPLE POWDER OF CASSIUS. 



M. Buisson states that in preparing this substance, he found that 

 the solution of gold always contains the same muriate, though it may 

 be mixed with more or less acid ; but he observes, that the solution of 

 tin, even when well prepared, contains two different muriates, and it 

 is upon their co-existence, within certain limits, that he conceives the 



N. S. Vol. 8. No. 47. Nov. 1830. 3 D goodness 



