Miscellanies. 191 



ting. Hence analysis may show a small deficit of charcoal below the 

 synthetic proportions originally iBixed. The residuum of charcoal and 

 sulphur left on the double filter paper, being well dried by the heat of or- 

 dinary steam, is estimated as usual by the difference of weights of the in- 

 ner and outer papers. This residuum is cleared off into a platina cap- 

 sule with a tooth-brush, and digested in a dilute solution of potash at 

 a boiling temperature. Three parts of potash are fully sufl[icient to 

 dissolve out one of the sulphur. When the above solution is thrown 

 on a filter and washed first with a very dilute solution of potash boil- 

 ing hot, then with boiling water, and afterwards dried, the carbon will 

 remain ; the weight of which deducted from that of the 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 acquire" says Dr. Ure, " how the maximum gaseous vol- 

 ume 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 ni- 

 trogen. This will lead us to the following proportions of these con- 

 stituents: — 1 prime equiv. of nitre 102 75.00 per cent. 

 1 do sulphur 16 11.77 

 3 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, 

 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 fol- 

 lows : 



Grains. Cubic inches. 



Carbonic oxide, - - 42 - - 141.6 



Sulpurous acid, - - - 32 - - - 47.2 

 Nitrogen, . . . 14 . . 47.4 



Being an expansion of one volume into 787.3. But as the tempera- 

 ture of the gases at the instant of their combustive formation must be 

 incandescent, 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." — Ideiii. 



