Prof. Regnault on the Specific Heat of some Simple Bodies. 103 



of lime to which Mr. Rainey has recently drawn attention as 

 occurring in animal tissues during the formation of shell*, 

 bone, &c, and which he has artificially produced by the slow 

 formation of carbonate of lime in the presence of gum or albu- 

 men. In all probability the physical forces concerned in the 

 building up of the calcareous and the siliceous globes are the 

 same. In many of the specimens of Beekite, the concentric 

 masses look as though they had been more perfect at one time, 

 but the outer portion had been disintegrated before the mass had 

 become thoroughly hard : at least they suggest that idea to 

 me ; and if true, that forms another link of analogy between 

 them and the phenomena described by Rainey. 



' ' It seems at first sight difficult to understand how, if the sili- 

 cification of, say a coral, begins on the outside all round, it can ad- 

 vance to the interior, and how the carbonate of lime within can be 

 removed; but it must be remembered that the silica, when first 

 deposited, was in the gelatinous condition, and permeable to 

 salts in solution, as Prof. Graham has shown in the case of other 

 of those substances which he designates ' colloids/ It is only 

 gradually that such a gelatinous globular mass would pass into 

 the rigid flint which we now handle. In the mean time, too, it 

 would be subject to all those changes of form, or that tendency to 

 cleavage, which pressure might superinduce. 



" It may be worthy of experiment to see whether the pellicle 

 formed by the gradual gelatinization of silica in solution ever 

 assumes a form at all corresponding with that of the Beekites. 

 " I remain, yours ever truly, 



"28 Pembridge Gardens, " J. H. GLADSTONE." 



Dec. 14, 1861." 



XVI. On the Specific Heat of some Simple Bodies, 



By M. V. REGN>ULTf. 

 [With a Plate.] 



I PURPOSE bringing together in the present paper the expe- 

 riments made in the last few years on the determination of 

 the specific heat of some simple bodies which I have hitherto 

 not been able to obtain in sufficient quantity or of adequate purity. 

 The methods which I have used, differ little from those which 

 served for my former investigations (Annates de Chimie et de 

 Physique, 2nd series, vol. lxxiii. p. 20) ; I have, however, ad van - 



* The structure of pearls, when compared with these globular bodies, 

 leads one to believe in their original identity, only the former are detached. — 

 A. H. C. 



t Translated from the Annales de Chimie et de Physique, September 

 1861, by Dr. E. Atkinson. 



