152 Intelligence and Miscellaneous Articles. 



acid, M. Bussy has arrived at the following conclusions : — 1st. The 

 vitreous, so far from being less soluble in water than the opake acid, 

 as stated by chemists, is, on the contrary, much more soluble. This 

 difference is nearly in the proportion of 3 to 1, at about 53° to 55° 

 of F. ; the same quantity of water which dissolves 36 to 38 parts of 

 the vitreous acid, will take up only 12 to 14 of the opake. 2nd. 

 The vitreous acid dissolves much more rapidly than the opake acid. 

 3rd. Neither of the varieties possesses a degree of solubility which 

 is to be regarded as strictly peculiar to it. 4th. The opake acid 

 is converted into vitreous acid by long boiling in water ; that is to 

 say, it then acquires the same degree of solubility as the vitreous 

 arsenious acid, which is such that 11 parts are dissolved by 100 of 

 water. 5th. Under the influence of water and a low temperature, 

 the vitreous acid is converted into opake acid ; that is to say, a solu- 

 tion of vitreous acid becomes reduced after a certain time to the 

 point of saturation which belongs to the opake acid. 6th. The mix- 

 ture of the two varieties of acid in the same solution explains the 

 anomalies observed in the solubility of arsenious acid, which in fact 

 offers nothing opposed to the principles admitted by chemists. 7th. 

 Division, which facilitates the solution of the opake acid, without 

 however increasing its solubility, considerably diminishes that of the 

 vitreous acid ; and to such an extent, that this acid, reduced to fine 

 powder and levigated, is not sensibly more soluble in water than 

 the opake acid ; this resulting unquestionably from a transformation 

 which it undergoes, either at the moment of pulverization, or of its 

 contact with water. 8th. Acid which has been rendered opake by 

 the action of ammonia, and acid crystallized in water, act similarly 

 with water, and appear to belong to the samevariety. 9th. The opake 

 acid dissolves more slowly than the vitreous in dilute hydrochloric 

 acid. This circumstance, which thus modifies the nature of the 

 products formed during solution, explains why the luminous phseno- 

 mena observed by M. Rose in the crystallization of the vitreous acid, 

 are not in general observable with so great intensity in the solution 

 of the opake variety. ] 0th. The difference which has been observed 

 in the action of the two arsenious acids on tincture of litmus is 

 merely apparent. If the opake acid does not redden the tincture, it 

 is on account of its slight solubility, and especially because it dis- 

 solves slowly ; whilst the vitreous acid, which dissolves quickly, 

 immediately reddens the tincture. But if comparative experiments 

 be made, and the tincture be exposed to the action of the powder, 

 it becomes gradually red, and no difference is perceptible at the ex- 

 piration of three or four days. — Comptes Rendus, Mai 1847. 



ON THE PREPARATION OF GUN-COTTON. 



Mr. Coathupe recently forwarded to the Chemical Society two 

 specimens of gun-cotton, with a view to illustrate the greatly in- 

 creased explosive effects that are to be derived from a subsequent 

 immersion of the gun-cotton, when properly prepared in the ordi- 

 nary way, in a saturated solution of chlorate of potash. 



