Prof. Regnault on the Specific Heat uf some Simple Bodies. 125 



Second specimen prepared by M. Rousseau. It was treated 

 by hydrofluoric acid; M. Rousseau feared nevertheless the pre- 

 sence of a little aluminium. 



M . . . 



llg r -38 



11^-18 



p . . . 



1^-332 



1^-332 



T . . . 



98°-25 



97°-95 



& . . . 



13°-54 



10°-32 



A<9' . . . 



0°7878 



0°-7928 



A . . . 



422& r -30 



422^-30 



C . . . 



. 0-2280 



0-2226 



Mean . 





0-2253. 



The specific heat of the second specimen is perceptibly less 

 than that of the first; and that proves clearly that even by the 

 same method products of different nature may be obtained. 



The third specimen was prepared by M. Debray in M. Deville's 

 laboratory, and by the same method. It consisted of very lus- 

 trous crystalline laminae, to some of which an amorphous sub- 

 stance adhered, from which it was very difficult to free them. 



M 



• • • 



. 21s r -00 



16s r -690 



P 



. . • 



. 1^-513 



3^-3472 



T 



. • 



. 99°-92 



99°-52 



& 



... 



. 10°-82 



16°-85 



Ad 1 





. P-4615 



l°-5938 



A 





. 422^96 



395^-58 



C 





. 02584 



0-2564 





Mean . 





0-2574 



This value differs little from that which I found for the first 

 specimen. 



In conclusion, I have but little confidence in the results 

 obtained for crystallized boron, and I shall assume that its spe- 

 cific heat is 0*250, which is about the mean of the numbers 

 furnished by the three specimens. If we write the formula of 

 boracic acid BoO 3 , the equivalent of boron becomes 136'1, and 

 the product of the specific heat, 0*250, by the equivalent is 34*1. 

 Thus, from the specific heat of crystallized boron, the most pro- 

 bable formula of boracic acid is BoO 3 . But it would be impru- 

 dent to draw any such conclusion from this fact ; for crystallized 

 boron might well contain another simple body, which would 

 materially modify its specific heat. 



