Reflections on some Miner a logical Systems, 387 



nutting in the molecule of filiated lime the necessary den- 

 sity to obviate this objection, we do not commit any indis- 

 cretion. 



Now let us take the contrary hypothesis, and say that 

 the molecules of all bodies have the same density, so that 

 the variation of specific gravity in them all depends solely 

 on the vacuums which exist between them. If in any 

 body whatever the quantity of vacuum be zero, we have 

 an absolute plenum ; and the heaviest body which we 

 know should be that which would present us with this 

 state of things. Platina furnishes us with an example, 

 while this collection of hypotheses contains the fact most 

 favourable to the objection. 



Chabaneau has found the specific gravity of platina to 

 be 2*400, others 2*300, some 2*200, and 1 have observed 

 it beyond 2*1 ; that of filiated lime is 3*191. Let us 

 simplify the expression of these relative weights, and we 

 shall have, in an equal volume, the quantity of matter in 

 platina, in fluated lime, and in water : : 1 : 4- : T l T . There is 

 then -f- of vacuum in fluated lime, or ££-, while the hypo- 

 thesis of M. Hauy notices only ±±. There remain, then, 

 ■iff more than are wanting to combat the objection. There 

 are also necessarily vacuums in other calcareous species. In 

 taking platina, as above, for an example of an absolute 

 plenum, we shall have, according to the data which the 

 specific gravity of this body furnishes, ~-f£ of vacuum in 

 carbonated lime ; -£f4 in phosphated as well as in filiated, 

 and £f£ in sulphated lime. The hypothesis of M. Hauy, 

 instead of being incompatible with what observation 

 teaches respecting the density of fluated lime, is not suffi- 

 cient to account for its lightness; and the -ffo of which it 

 takes no notice, as well as the vacuums in other species 

 which are passed over in silence, are so many particular 

 cases of a verity demonstrated in physics : its great noto- 

 riety doubtless made M. Haiiy believe that it was unneces- 

 sary to anticipate this objection by answering it at first. 

 Instead, therefore, of accusing him of having carried off' 

 too much matter from fluated lime as a mineralogist, we 

 should rather consult him as an examiner of nature {physi- 

 cien) 9 on the fate of nearly -±-£ of which he is silent. It is 

 difficult to conceive how any one could permit himself to 

 make such objections, especially when we consider ike 

 source whence \hey sprung, 



r l lie divisibility or carbonated lime before mentioned, by 

 supersections which yield molecules of two different 

 iorms, and also what we have just observed respeeting the 



2 B 2 oetaedron 



