Chap. XVI.
TABLE OK SPECIFIC GRAVITIES.
1117
than that of the body, then the part immersed is less than that of the whole solid, and thebody will float. The specific gravity of the solid is therefore to that of the fluid in whichit is weighed, as the absolute weight of the solid is to the loss of weight which it sustains.
In the following table all the measures are related to that of water, whose specificgravity is 1 *000. To ascertain the weight of either of the substances contained in thefollowing table, it is only necessary to compare it with the weight of a cubic foot of water,which weighs nearly 1000 ounces avoirdupois, or more nearly 998. Thus a cubic foot ofnative gold would weigh 170,000 ounces, or 1000 multiplied by 17, its specific gravity:platina, which is one of the densest metals, is 23 times as heavy as distilled water; finegold 19J; mercury 13J; lead 11^; silver II ; copper 9; iron and steel 7J; stone 2.}; andfir timber only half the weight.
This method of ascertaining the bulk of bodies was first discovered by Archimedes : butin all experiments made it is necessary to consider that a considerable change of the jointbulk of any two substances tried is often produced by their mixture, and generally theirdimensions are considerably contracted. 18 gallons of water, mixed with 18 gallons ofalcohol, will make only 35 gallons, and therefore the specific gravity of such a compoundis one-thirty-fifth greater than the mean of the specific gravities of the two ingredients :iron also by an addition of one-eighth of its bulk of platina becomes contracted one-fortiethof the whole bulk.
A Table of Specific Gravities.
Metals.
Antimony, nativefused
glass of -grey
sulphur ofore grey and foliatedradiated
red
fusedbloomglass ofpyritesBismuth , native
fused
sulphuretted
ochre
Brass, common cast -wire drawncast, not hammered -Cerite -
Cobalt, fused - - -
ore grey
earthy black indurated
vitreous oxideColumbium -
Copper native -
fused -
Copper ores ore compact vitreousCornish -
6*720f 6*624( 6*8604*94644*3
4*96434 *3684*440
3 750
4 *0905*670
5 6006*5228*3102 640
. 3*5942
6 *59*570
{ 9*7569*8229 0706*1314 371■ 7*824
. 8*544
8*3954*5
f 7*645\7*81if 5*511(7*721f 2*019(2*4252*44055 918f 7*600■(7*8008*50847*728f 7*788L 8*8954*1295*452
Copper, purple, from Bannatfrom Lorraine
glance -pyriteswhite -grey -yellow -blue -
foliated florid red -azure radiated
- 4 *!>.'Jt>
f 4 3004*983(5*467
4 *956•30013*4675*6f 4*080" \ 4*344- 4 500
*865*54 3
emerald
muriate ofarseniate, hexaedraloctoedraltrihedralprismatic -partial arseniatesulphate, solution sat. 42*'wire -
-I 4 ' 8
t4*5
- 4 3_f32
(3*4
- 3-95f 3 *23
~\ 3-60Jf 2 850‘(3*300
Gold, native
3- 95011
■6088501004*42 5492*884*2
4- 23*41*1508*878
f 17*00\ 19 00
pure, fused, 24 carats fine 19*2587same, hammered - - 19 -342
fine, fused, not hammered 18*888guinea George II . - - 17*150
Paris standard 22 carats
not hammered - - 17*486
same, hammered - - 17*589
Holland ducats - - 19*352
trinket standard 20 carats,
not hammered - - 15*709
same, hammered - - 15*775
fused- - 17*4022