[ 549 ]

in water 217.885, from which numbers the ipecisic gravitycomes out 19.387.

Specific Gravity

Platinas

By Exper.

By Calcul.

Difference

Gravity

LEAD

11,386

resulting

Platina 1, Lead 0,97

14,029

i 3> 6 79

' 35 °+

OO

0

Platina r, Lead 1,92

12,925

12,838

,° 8 7 +

x 7'459

Platina 1, Lead 3,97

12,404

12,196

, 3 o8 +

19,242

Platina 1, Lead 8 -

"'947

11,819

,128-j-

19,732

Platina 1, Lead 12 -

">774

11,682

'092+

19,923

Platina 1, Lead 24 -

"'575

OO

,° 37 +

19-238

From this table it appears that the gravity of lead is af-fected by crude platina in a different manner from that ofgold; the mixtures with gold being such, as if the crudegrains were of less gravity than 17, but those with lead asif they were of greater; so that in one or the other case, orin both, an alteration of volume must necessarily be pro-duced by the action of the two metals on one another.

SpecificGravity

S I LVE R

By Exper.

10,980

By Calcul

Difference

Platina 1, Silver 1 —

13'535

13,342

"93 +

Platina 1, Silver 2 —

12,452

I 2,449

,°°3 +

Platina r, Silver 3 —

",790

I 2,046

,256 —

Platina 1, Silver 7 —

10,867

I 1,488

,621 —

Here we fee the effects of the ebullition and dispersionof the silver taken notice of in the history of the fusion ofplatina with this metal. The last mixture is lighter eventhan silver itself, a proof that the metal is rarefied or madecavernulous by the action of the platina : the greater gra-vity of the two first mixtures was probably owing to a partof the silver having been thrown off in the fusion, and the

B b b b 2 platina