832 FORMYL. 



soluble in water and more so in alcohol and ether. Potassium 

 decomposes it with effervescence ; but neither the aqueous nor 

 the alcoholic solution of potash has any effect upon it.* 



COMPOUNDS OF FORMYL WITH CHLORINE, BROMINE AND IODINE. 



Protochloride offormyl, C 2 HCl=FoCL One of the subs- 

 tances which Regnault obtained by the action of chlorine upon 

 chloride of acetyl, namely C 4 H 2 C1 2 , is considered by Liebig as 

 protochloride of formyl, its atomic weight being divided by 

 two. 



Bichloride offormyl, C 2 HCl 2 =FoCl 2 ; one of the substances 

 formed by the action of chlorine upon chloride of ethyl, namely 

 C 4 H 2 C1 4 , is so considered by Liebig, its atomic weight being 

 divided by two. 



Perchloride offormyl, chloroform, C 2 HCl 3 =:FoCl3. This 

 compound is formed in various circumstances. It may be 

 prepared by exposing a mixture of chloride of methyl (C 2 H 3 C1) 

 and gaseous chlorine to the direct rays of the sun ; by distilling 

 chloral with barytes-water or milk of lime but most conveniently 

 by distilling a dilute solution of chloride of lime with acetone, 

 alcohol or wood spirit. For this purpose 1 part of hydrate of 

 lime is suspended in 24 parts of water, a current of chlorine 

 sent through it till the greater part of the lime is dissolved, and 

 a little milk of lime added to make the liquid alkaline. When 

 the solution of chloride of lime has become clear by repose, 

 ^th of its volume of alcohol is added, and after being left to 

 itself for twenty four hours, the liquid is distilled by a gentle 

 heat in a capacious retort. The product has an ethereal odour, 

 and contains perchloride offormyl mixed with alcohol, on shaking 

 it with water the perchloride separates as a dense liquid, and 

 may be obtained perfectly pure by digesting it upon chloride 

 of calcium, and distilling it again with concentrated sulphuric 

 acid. (Liebig's Traite). 



Perchloride of formyl is a colourless oily liquid, of an agree- 

 able ethereal odour and sweetish taste ; its density is 1.480 at 

 64.4 (18 centig.) 3 its boiling point 141.44 (60.8 cent.) It 



* Dr. Stenhouse, Phil. Mag., 3rd Series, vol. 18, p. 122. 



