376 CHLORINE. 



pounds may be traced up to alcohol, the substance from the 

 decomposition of which, indeed, this whole class of compounds 

 is primarily derived. Thus acetyl with two equivalents of hydro- 

 gen forms a higher compound radical ethyl C 4 H 3 , H 2 or C 4 H 5 , 

 of which ether is the oxide, and alcohol the hydrate of 

 that oxide. In both the acetyl and ethyl series, it will be ob- 

 served that the proportion of carbon (C 4 ) is constant, being 

 that originally present in the alcohol, and we shall find it in the 

 chloride of carbon, which is the last product of reducing pro- 

 cesses upon alcohol. Olefiant gas itself is a hydruret of acetyl 

 that is, C 4 H 3 ,H. When exposed to chlorine, both the acetyl 

 and hydrogen combine with chlorine, giving the Dutch liquor, 

 C 4 H 3 ,C1 + HC1. Comparing the formula for olefiant gas with 

 the first part of the last formula, C 4 H 3 , H with C 4 H 3 , Cl, it 

 will be found that in losing an atom of hydrogen the ole- 

 fiant gas has acquired an atom of chlorine ; and this is an ins- 

 tance of the law of substitution which Dumas has traced to so 

 great an extent in the formation of organic compounds. When 

 a stream of chlorine gas is transmitted through the Dutch li- 

 quor, Regnault finds that another atom of hydrogen is carried 

 off, as hydrochloric acid, and an atom of chlorine left in its 

 place; thus the Dutch liquor, C 4 H 3 C1 + HC1 becomes 



C 4 H 2 Cl 2 -fHCl. 



This second product, which is a liquid, being submitted to 

 the action of a stream of chlorine, was found to give rise to a 

 third liquid product, in which the hydrochloric acid of the last 

 formula had disappeared, and the remaining portion had as- 

 sumed two additional atoms of chlorine, forming 



C 4 H 2 C1 4 . 



This third liquid, is changed by the prolonged action of 

 chlorine into the perchloride of carbon, but to hasten the action, 

 it is convenient to conduct the operation in the light of the 

 sun ; its two atoms of hydrogen being carried off in the form 

 of hydrochloric acid, and two atoms of chlorine left in their 

 place, which gives the formula 



Perchloride of carbon. . . C 4 C1 6 , or C 4 C1 4 -J-C1 2 . 



Now this view of derivation and constitution of the per- 

 chloride of carbon, is confirmed by the density of its vapour 



