Intelligence and Miscellaneous Articles. 153 



These numbers, it is observed, though very nearly approaching those 

 which give the formula C-*^ H"', generally admitted, show an unusual 

 excess of carbon; this circumstance was notified to M. Laurent, who 

 was long occupied with naphthalin in theoretic considerations, and 

 it is to be regretted that it did not receive his attention. 



The recent analysis of naphthalin by Liebig also exhibits the same 

 excess of carbon. 



Carbon 94-3 .... 94-2 . . . 94-6 



Hydrogen 6"2 .... 6*1 .... 6"1 



100-5 100-3 100-7 



The analysis of naphthalin is then decidedly different from that of 

 the formula attributed to it. M. Dumas therefore considered it 

 necessary to undertake some experiments on the naphthalin of resin, 

 in order to compare it with that of coal. 



Five experiments upon the naphthalin from the resin oil gave : 

 I. II. III. IV. V. 



Carbon. . 94-2 94-2. . . . 94-27 94-9 94-9 



Hydrogen 63 6-3 6-26 6-2 6-1 



100-5 100-5 100-53 lOO'l 100- 



M. Dumas then again analysed coal naphtha, and the results were 



I. n. m. 



Carbon 94-55 94-2 94-55 



Hydrogen. . 6-50 6-3. . . . 6-20 



101-05 100-5 100-75 

 In some of these analyses the quantity of carbon only was deter- 

 mined, which introduced errors into the hydrogen, that are usually 

 avoided. As the hydrogen was never less than 6-2, it maybe ques- 

 tioned whether the formula for naphthlalin ought not to be replaced 

 by that by Liebig, which is, 



C« 1528-7 94-23 



H'^ 93-6 .... 5-77 



1622-3 100- 



On the other hand, it may be readily perceived, that a slight error 

 in the atomic weight of carbon would be sufficient to explain the 

 discrepancies between calculation and direct analysis ; an example 

 will immediately show this : 0-387 of naphthalin gave 1-318 of car- 

 bonic acid and 0-220 of water, which according to the atomic weight 

 attributed to carbon, would give 94-2 per cent, of carbon in naph- 

 thalin. 



But on the supposition that the atomic weight of carbon should 

 be reduced to 38 instead of 38-6, [z. e. 6-08 hydrogen=l.] this ana- 

 lysis would be represented as follows : 



Carbon 93-8 



Hydrogen 6-2 



100- 



