486 Intelligence and Miscellaneous Articles. 



ing for an hour, and pulverized transparent arsenic was gradually 

 added. There were dissolved 95*1 gr. Hence, 



1000 gr. water dissolved (95- 1-*- 2) .... 47*55, or t^. 

 From this solution there were deposited, in crystals, after 48 hours, 

 68*3 gr. Hence, 95-1 -68-3=26 8—2= 134 gr. 

 1000 grains of water, held dissolved, on perfect cooling, 13*4 grains, or^. 

 The results of these experiments show, that there is certainly not al- 

 ways the difference in the degree of solubility of these two varieties of 

 arsenic, which M. Guibourt suspected ; and which, upon his author- 

 ity, is to be found stated in many chemical and medico-legal works. 

 The quantity dissolved, of either variety, under similar circumstances, 

 according to these experiments, may be regarded, for all practical 

 purposes, as the same. 



'* In cases of criminal poisoning, it occasionally happens that cold or 

 temperate water is used as the solvent for this poison, and a witness 

 is expected to state the degree of its solvent powers. The considera- 

 tion of this, led to the performance of the following additional expe- 

 riments. 



" Exp. 9. Eight fluid ounces of temperate water were poured upon 

 twenty grains of the pulverized opaque arsenic, in a clean glass vessel. 

 The powder immediately collected in lumps, which partly floated and 

 partly remained at the bottom of the vessel. A slight film of powder 

 formed by repulsion on the surface of the water. The vessel was 

 covered over, and allowed to stand 72 hours, having been first well 

 agitated. The liquid was filtered, and the filter carefully dried. The 

 residual undissolved powder weighed 1 6 gr. And20— 16=4. Hence, 

 1000 gr. water (f^ij.), dissolved .... 1 gr. or -r^Vir* 



Twenty-five grains of the filtered solution, evaporated, left '03 gr. • 

 which is nearly equal to the proportion above determined from the 

 undissolved residue. 



" Exp. 10. Another experiment was performed, which only differed 

 from the preceding in the circumstance of the vessel having been fre- 

 quently agitated. The undissolved powder left on the filter, after dry- 

 ing, weighed 1 1*5 gr., and 20— 1 1*5 =8"5 gr. Hence, 



1000 gr. water (f^ij.), dissolved .... 8'5-r4=2125 or «}*. 



Twenty-five grains of the filtered solution were evaporated ; and left 

 not quite -06 gr., a proportion rather larger than that above deduced. 



" It follows, from these experiments, that very nearly the same quan- 

 tity of arsenious acid is taken up by hot water allowed to cool, and 

 cold water poured on this substance in powder ; provided the vessel 

 containing the cold water be frequently agitated. They also show 

 the necessity for a continued application of heat, in order that the 

 poison should be dissolved in any considerable quantity. It is a cu- 

 rious, and hitherto an unexplained fact, that water should retain so 

 much more of this poison, as from ten to twenty times the quantity, 

 when perfectly cooled from a boiling saturated solution, than it will 

 take up at common temperatures without heat. It would seem to 

 indicate, that heat must excite some permanently powerful affinity 



