ALDEHYDES. 277 



sequently into chloral, which, upon being treated with alkalies, 

 is decomposed into an alkaline formate and chloroform. 



The action of the chlorine of the calcium hypochlorite (which 

 is the active principle in bleaching-powder) upon the alcohol is 

 similar to that of free chlorine upon alcohol ; in both cases 

 aldehyde, and afterwards chloral, are formed, which latter, in 

 the manufacture of chloroform, is decomposed by the calcium 

 hydrate into calcium formate and chloroform. 



If the various intermediate steps of the decomposition are not 

 considered, the process may be represented by the following 

 equation : 



4C 2 H H O + 8CaCl 2 O 2 = 2(CHC1 3 ) + 3(Ca2CHO 2 ) + 5CaCl. 2 + 8H 2 O. 



Alcohol. Calcium Chloroform. Calcium Calcium Water, 



hypochlorite. formate. chloride. 



Pure chloroform is a heavy, colorless liquid, of a characteristic, 

 ethereal odor, a burning, sweet taste, and a neutral reaction ; 

 it is but very sparingly soluble in water, but miscible with alco- 

 hol and ether in all proportions ; the specific gravity of pure 

 chloroform is 1.50, but a small quantity of alcohol (from one- 

 half to one per cent.), allowed to be present by the U. S. P., 

 causes the specific gravity to be about 1.488 ; boiling-point 

 about 60, but rapid evaporation takes place at all temperatures. 



Chloroform should be tested for excess of alcohol by specific 

 gravity ; for hydrochloric acid and chlorine by shaking it with 

 water, which should not give a precipitate with silver nitrate ; 

 for aldehyde by heating with solution of potassium hydrate, 

 which should not be colored brown ; for empyreumatic and other 

 organic compounds by shaking with an equal volume of pure 

 sulphuric acid, which should remain colorless; or by evaporation, 

 when no residue should be left and no odor should be per- 

 ceptible after the chloroform has been volatilized. 



The only characteristic test for chloroform consists in passing 

 its vapors through a glass tube heated to redness, when chloro- 

 form is decomposed, a deposit of carbon being formed, whilst 

 chlorine and hydrochloric acid escape, and may be recognized 

 by their action on silver nitrate (white precipitate of silver 

 chloride) and mucilage of starch, to which potassium iodide has 

 been added (free chlorine liberates iodine, which forms with the 

 starch blue iodized starch). In applying this chloroform test 



