408 



The value 10.5 for nucleu.s-carbon tliu.s adapt« it.self well eillier 

 for benzene or ils liomologue« ; and in tli^' deducing of such special 

 vahies for carbon or hydrogen or for bolh, the amniatic ////^//-ocvn-ZwHs 

 are certainly the nicst auitable, a.s they consist of carbon and hydrogen 

 alone and do jiot contain oxygen or nitrogen, Ihe presence of 

 which introduces elements of uncertainty. 



The above Aalue of carbon may, however, he employed in the 

 same manner in calculating the specific volumes of simpler aromatic 

 compounds containing oxygen, the twn values given to this element 

 by Kopp being adopted in the calculatii^i. Thus — 



Obser \ c( i . Calculated . 



(Kopp.) = 10.5 & 11, H = 5.5. 



= 12.-J & 7.8. 



ITienolC, II5. O'll 103. G 103.8 



Benzoic aldehyde C, H5. CHO" 118.1 \l'J.-2 



Benzoic acid C, H,. CO'O' H li^li.!) li'7.0 



Ethyl b^nzoate C,; H,-,. CO'0"a II5 ... 1 7iM— 1 71,.S 171.0 



Beijzylic alcohol C, 11,. Clf, UH li\-;.7 li'.-).8 



Mr. Kuhara, in \'<)1. II, l*t. 1\ of thi._-j(jurii:il, calculated the 

 specific Aolumes for the above liodies, using ]>ö.^l■hmidt's constants 

 and on the suj)positioii that 3 atoms of carbon ii;i\c ihe \alue 11, the 

 rest 11, and that hydrogen, Avhciher of I he nucleus or of tlu^ side- 

 chain, i)ossessei5 the constant value 3.."). lie will find ihat his num- 

 bers are not more concordant wilh the experimental values than are 

 those above calculated. If, moreover, he tried his method of calcula- 

 tion upon the aromiitic iiijdroaiyhtum. — bodies \\hich, a..; 1 already 

 pointed out, are certain! v best suited to test the accuracy or utility of 

 the constants for carbon and hvdrogeii — he will g\'t very dilferenl 

 results, as 1 have already broadly indi'aird and a- (he following table 

 will -Ikjw in greater del ail : — 



