Dr. Ure on Chloride of Lime. 3 



weights of lime and water, instead of the jiroto-hydrate. This, 

 however, would not, I believe, answer well in practice on the 

 large scale, as the surface of the lime would become somewhat 

 coherent, and prevent the interior from readily receiving its 

 fair dose of chlorine, without an inconvenient degree of mani- 

 pulation. The distant bleacher would likewise grudge to pay 

 for the carriage of this extra water. Mr. Dalton likewise re- 

 marks, that " In whatever stale we procure the oxymuriate of 

 lime," (of commerce,) " it is always found to be accompanied 

 by a portion of muriate of lime ; this portion, too, increases 

 with the age of the oxymuriate, and is furnished at its expense. 

 It becomes a primary object of analysis, then, to ascertain 

 how much of any given specimen is muriate, and how much 

 oxymuriate, especially as the former is of no use in effecting 

 the purposes to which the latter is applied *." His analytical 

 conclusion, from the experiments on Mr. Tennant's salt, is the 

 following : " Hence we may infer, that this is the saturation 

 which is produced from the process of making dry oxymuriate 

 of lime ; namely when atom of the acid is combined with two 

 atoms of lime : so that the salt may be denominated the sub- 

 oxymuriate of lime. When dissolved in water, one half of 

 the lime is deposited, and a solution of simple oxymuriate 

 is obtained!." 



In the second paper, on Dr. Henry's oxymuriate, where he 

 shews that the muriate is an accidental, and not an essential, 

 concomitant of the other, we find another method of analysis 

 proposed. " It is to dissolve a known weight of the oxymu- 

 riate in a small portion of water ; then put the liquid into a 

 graduated tube over mercury, and discharge the gas by an 

 acid ; it may thus be measured, and the quantity retained by 

 the liquid may be estimated at twice the bulk of the liquid 

 nearly. The gas may, I find, be kept in the tube under these 

 circumstances for a week, without losing more than 40 or 50 

 measures" (out of 170 measures) " of its volume; so that its 

 combination with mercury is slow, if not agitated. Upon the 



* Annals of Philos. I. p. 16, f Idem, p. 19. 



B2 



