14 § G. REAGENTS. 



phuric acid so that the filtrate from the precipitate leaves 

 no residue when evaporated, and it should give no reac- 

 tion with argentic nitrate. 



€. Calcic chloride. — CaCl^. (Chloride of calcium. CaCl.) 

 — This should not affect litmus-paper, should give no 

 reaction with ammonic sulphide, nor any ammonia when 

 heated with sodic hydrate. Dissolve the crystals in 5 

 parts of water. 



The crude, impure, fused chloride answers for desicca- 

 ting purposes. 



/. Calcic fluoride.— CaF^. Fluor spar. — To cave 

 trouble, buy the powdered fluor spar. 



g. Calcic hydrate. — Ca(HO) 2. Lime-water. (CaO, 

 HO.) — Digest slaked lime with cold water with occasional 

 stirring, let the mixture stand quietly for a time, and de- 

 cant the clear liquid for use. It should give a dark color 

 to turmeric-paper, and a considerable precipitate with 

 ammonic oxalate. 



For many purposes milk of lime is used in preference 

 to lime-water ; this reagent is simply lime-water, mixed 

 with an excess of undissolved calcic hydrate. It should 

 be made with lime from white marble, and should be kept 

 in well stoppered bottles, and shaken up Avhen used. 



A. Calcic sulphate. — CaSO^. (Sulphate of lime. CaO, 

 SO3.) — Digest powdered, crystallized gypsum a long time 

 Avith cold water, with frequent agitation, let the mixture 

 stand quietly at last, and decant the clear liquid for use. 



6. Chlorine. — CI. — Nearly fill a flask with manganic 

 binoxide in pieces about as big as peas, and then add so 

 much common, concentrated hydrochloric acid, that about 

 half the oxide will be immersed in it. Conduct the gas, 

 by a glass tube passing through the cork with which the 

 mouth of the flask is closed, through a cylinder or wash- 

 bottle containing concentrated sulphuric acid. The eve- 



