464 



remained undetermined, and corrected such as had been inaccu- 

 rately observed. In the present paper the author has collected his 

 experimental determinations, and has given a survey of all the facts 

 satisfactorily established up to the present moment regarding the 

 relations between boiling-point and composition. 



The several propositions previously announced by the author 

 were : 



1. An alcohol, C n H w+2 O2, differing in composition from ethylic 

 alcohol (C 4 H 6 O 2 , boiling at 78 C.) by x C 2 H 2 , more or less, boils 

 #X 19 higher or lower than ethylic alcohol. 



2. The boiling-point of an acid, CH n O 4 , is 40 higher than that 

 of the corresponding alcohol, C w H n+2 O 2 . 



3. The boiling-point of a compound ether is 82 higher than the 

 boiling-point of the isomeric acid, CH n O 4 . 



These propositions supply the means of calculating the boiling- 

 points of all alcohols, C n H w+2 O 2 ; of all acids, C n H n O 4 ; of all com- 

 pound ethers, C W H W O 4 . The author contrasts the values thus cal- 

 culated for these substances with the available results of direct obser- 

 vation. The Table embraces eight alcohols, C n H w + 2 O2, nine acids, 

 CH n O 4 , and twenty-three compound ethers, C n H w O 4 ; the calculated 

 boiling-points agree, as a general rule, with those obtained by experi- 

 ment, as well as two boiling-points of one and the same substance 

 determined by different observers. We are thus justified in assuming 

 that the calculated boiling-point of other alcohols, acids, and ethers 

 belonging to this series will also be found to coincide with the results 

 of observation. 



The boiling-points of other monatomic alcohols, C w H m O 2 , other 

 monatomic acids, C W H TO O 4 , and other compound ethers, C n H m O 4 , 

 are closely allied with the series previously discussed. A substance 

 containing xC more or less than the analogous term of the previous 

 class, in which the same number of oxygen and of hydrogen equiva- 

 lents is present, boils xx 14*5 higher or lower ; or, what amounts to 

 the same thing, a difference of #H more or less of hydrogen lowers 

 or raises the boiling-point by ^x5. Thus benzoic acid, C U H 6 O 4 , 

 boils 8 x 14- 5 higher than propionic acid, C 6 H 6 O 4 , or 8 x 5 higher 

 than renanthylic acid, C 14 H 14 O 4 ; cinnamate of ethyl, C 22 H 12 O 4 , boils 



10 x 14' 5 higher than butyrate of ethyl, C 12 H 12 O 4 , or 10 X 5 higher 

 than pelargonate of ethyl, C 22 H 22 O 4 . 



