1:3-1 Prof. Regnault on the Specific Heat of some Simple Bodies. 



It appears, from this that amorphous boron, in becoming 

 cooled in hydrogen gas, had condensed in its pores a large quan- 

 tity of this gas. The gas took tire in air just as is the case 

 when hydrogen is directed on spongy platinum. 



2. Graphitoidal Boron. 



This was prepared by M. Debray, by accurately following the 

 method described by M. Deville. It was in small lustrous laminae, 

 closely resembling those of graphite. 



M . 



. . 13^86 



I8**87 



13^56 



P • 



. . 6^-593 



6^-593 



6* r -593 



T . 



. . 99°-32 



99°-72 



99°-27 



d f . 



. . 16°-64 



18°-09 



17°-41 



A0' . 



. . P-9117 



1°-8814 



l°-9272 



A . 



. . 4228*96 



422s r -96 



422^-96 



C . 



. . 0-2299 



0-2275 



02481 





Mean . . , 



. . . . 0-2352 



The results obtained by these experiments differ appreciably 

 from each other. This arises from the fact that, in order to 

 retain this pulverulent boron in the brass basket, it was neces- 

 sary to line the latter with lead-foil ; and in order that the 

 basket should sink rapidly in the water of the calorimeter, it had 

 to be loaded with a disc of lead. The calorimetric value of p is 

 thus twice that of M ; and the latter, which is the unknown, 

 necessarily bears the sum of the errors of each experiment. 



3. Crystallized Boron. 



Crystallized boron is prepared, according to M. St. -Claire 

 Deville, by heating aluminium in a porcelain tube in a current 

 of chloride of boron. 



I worked with three specimens prepared by this method. 



The first specimen was lent me by M. Deville : the quantity 

 w T as not great ; and it was necessary to take special precaution to 

 obtain accurate results. The following are the elements of the 

 three experiments which I made : — 



M . 



. . 7^330 



7^-280 



7& r -202 



P 



, . . 0^-2826 



0^-2413 



0s r -2413 



T . 



. . 97°-60 



97°' 73 



97°-67 



& . 



. . 10°-52 



9°-35 



10°-26 



A0' . 



. . l°-4436 



l°-3750 



l°-3350 



A . 



. . 134^-566 



134^-846 



141^-076 



C 



. . 0-2657 



0-2552 



0-2652 





Mean 



. . 02622 





