Dr. Ure un Chloride o/' Lime. 



21 



m 



and the arts, however, the following very simple plan will very 



generally suffice. Get a glass tube, of 



about five cubic inches capacity, shaped as 



in the adjoining figure, and graduated into 



cubic inches and tenths. It is to be closed 



at top with a brass screw cap, and, at its 



recurved end below, with a good cork. 



Pour mercury into the upper orifice, till 



the tube be nearly full ; leaving merely 



space to insert 10 grains of the bleaching- 



powder, made into a pellet-form, with a 



drop of water. Screw in the cap-plug, 



rendered air-tight by leather. Remove 



now the cork from the lower end, (also full 



of mercury,^ and replace a little of the 



liquid metal, by dilute muriatic acid (sp. 



gr. 1.1). By dexterous inclination of the 



instrument, the acid is made to flow up 



through the mercury. Instantly on its coming into contact 

 with the pellet, the chlorine is disengaged, the mercury flows 

 out into a basin ready to receive it, while the resulting film of 



present, the gas may be received over mercury, as formerly described.) 

 Evaporate the solution, consisting of acetate and muriate of lime [to dry- 

 ness, by a regulated heat, and note the weight of the mixed saline mass. 

 Then calcine this, at a very gentle red-heat, till the acetic acid be all de- 

 composed. Note the loss of weight. We have now all the data requisite 

 for determining the proportion of the constituents without solution, filtra- 

 tion or precipitation by re-agents. 



Problem I. — To find the lime originally associated with the chlorine, or 

 at least not combined with muriatic acid, and therefore converted into an 

 acetate. Rule. — Subtract from the above loss of weight, its twenty-fifth 

 part, tlie remainder is the quantity of lime taken up by the vinegar. 



Problem II. — To find the quantity of muriate of lime in the bleachiug- 

 powder. Rule. — Multiply the above loss of weight by 1.7, the product is 

 the quantity of carbonate of lime in the calcined powder, which being sub- 

 tracted from the total weight of the residuum, the remainder is of course 

 the muriate of lime. We know now, the proportion of chlorine, lime, and 

 muriate of lime in 100 jimIs; the deficiency is the water existing in the 

 bleaching-powder. Thus, for example, I found 1 00 grains of a commercial 

 chloride sometime kept to give off 21 grains of chlorine, by solution in dilute 

 acetic acid. The solution was evaporated to dryness ; of saline matter 



