Mr. Fownes o« the Equivalent of Carbon, 63 



stance employed. As an illustration may be adduced, three 

 of the analyses latel}' made in the Giessen laboratory by M. 

 Woskresensky, 100 parts of naphthaiin gave 



Carbon... 94,625 94,4.94- 94,395 



Hydrogen 6,528 6,526 6,206 



101,153 101,020 100,601 



In repeating these experiments with great care by the aid of 

 Professor Liebig's process, results differing little from the 

 foregoing were obtained. 



The specimen of naphthaline employed was purified by very 

 slow sublimation in a Florence flask, by which means it was 

 obtained in large crystalline plates of the most brilliant 

 whiteness. In this state it had very little odour when cold, 

 and melted on the application of heat to a colourless, trans- 

 parent fluid, which crystallized confusedly on cooling: 



(1) 4*338 grs.naphth. gave 14*82 grs.carb. acid and 2*45 water 



(2) 4-944 16-93 2-78 — 



(3) 4*87 16*67 2*72 — 



(1) (2) (3) 



Carbon... 94-46 94-68 94'65 



Hydrogen 6-27 6-25 6*21 



100-73 100-93 100-86 



As the error of excess here to be observed exceeds the usual 

 limit of inaccuracy of the experiment, no other supposition re- 

 mains but that of M. Dumas, that the equivalent of carbon 

 may be taken too high. 



Bicarburet of hydrogen, the benzin of Mitscherllch, being 

 apparently a substance of very definite nature, it was thought 

 that some additional light might be obtained from an analysis 

 of this liquid. It was carefully prepared in the manner de- 

 scribed by its discoverer, by slowly heating to dull redness in 

 a capacious earthen retort, a mixture of 4 ounces of crystal- 

 lized benzoic acid and 12 of hydrate of lime. The condensed 

 oily liquid being separated from the water on which it floated, 

 agitated with fragments of caustic potash, and finally redi- 

 stilled from a large quantity of recently fused and powdered 

 chloride of calcium, after having stood some days in contact 

 with that salt, had a specific gravity = -885 at 60° ; refracted 

 light strongly, and boiled in a glass tube at 177° Fahrenheit. 

 Burned with oxide of copper. 



