190 Dr. Hermann Kopp on a great Regularity in the 



Atomic 

 weight 



Specific volume. 



Density. 



Observed. I Calculated. Calculated. I Observed. 



Hydrate and JEther of Acetic Acid. 



A4-H'0 I 

 A+AeO I 



F+H2 ! 

 F+AeO I 



Su+AeO 



753 

 1107 



r09 



1243 



1-062 

 0-89 



. 0-8906 ] 



Hydrate and iEther of Formic Acid, 



467 i ... I ... I 1-2353 I 

 1001 0-9293 0-912 



577 

 930 



Mollerat. 

 Liebis 15° C. 



Liebig 12°. 



Hydrate and .^fher of Succinic Acid. 

 741 I 478 I ... I ... I l-oo I Richter. 

 1094 ... 1012 1-0812 1-036 D'Arcet. 



II. "Tlie specific volume of a h\'drated acid (A+H'O) is 

 300 smaller than that of the corresponding methyl compound 

 (A+ Me O)." 



To test the correctness of this law, let us, as above, calcu- 

 late the density of the methyl compound from the observed 

 density of the hyd rated acid, by adding 300 to the specific 

 volume of the hydrated acid as resulting from observation, 

 and dividing the atomic weight of the methyl compound by 

 this sum, which is the calculated specific volume. The quo- 

 tient which is the calculated density of the methyl compound 

 may then be compared with that obtained by experiment. 



III. "The specific volume of each sethyl compound is SS* 

 greater than that of the corresponding methyl compound." 



