I N D
Gold adulterated with it — 445, 6c;
Its mineral history — —-60}
History of its introduction into Europe
-442
Supposed to be contained in some Euro-pean minerals-— 608
hence the use of such minerals for the
augmentation of gold-608
History of experiments made on it bydifferent persons-445
Platina, Description of—-449.
Substances mixed with it-450
Quantity of gold separated from it 596
Malleability-4;;
Gravity, nearly equal to that of goId4;z
Effects of (ire on it-4;6
Gains weight in the sire-459
the increase owing to its admixtures^ tNot fusible in fires that vitrefy all com-mon vessels and furnaces 458, 462,
---— 463, 468
Melted by burning glass-466'
Resists the simple acids, equally with
gold-- 469 feq.
Dissolved, like gold, in certain circum-stances, by marine acid — — 472Dissolved, like gold, by aqua regia 47;Quantity of menstruum necessary 476Colour of the solution, and trials for
staining-478
Volatilization of the platina-480
Crystallization-479
Precipitation by different alcalies 481Not precipitated by mineral alcali 483Precipitated in part by sal ammoniac 48;Not separated from its solution by vi-nous spirits — —-48;
Not imbibed by essential oils or æther
-486
Produces no purple with tin-487
Precipitates exposed to burning glafsqsiSGlass melted with the precipitates in
strong fires- 503
Its particles agglutinated by fire into a
metalline lump-4-,7, ;o;, 370
Exposed to strong fires with various
fluxes —-489
Divided,and an irony matter separated,by long cementation with nitre 491Diflolvcd, sparingly, by sulphurated al-cali -502
Unites intimately with all the commonmetals —-544.
E X.
Strong fire necessary for its perfect so-lution by metals---340
Produces with them compounds of new
qualities-339, 340
Examination of the specific gravities of
the compounds-— 34',
The gravityof platina not deductible fromthat of any mixture of it with other
metals — — —-333
Amalgamation of it with mercury 508
fusion with arsenic-3 , 3
Bismuth —-— — 309
Brass--3 3 2
Gold — — — — -— — — 323
Iron--— — 3,4
Lead-5^2
Regulus of antimony-321
1 in--—> 310
Silver — — —-— 522
Zinc--3,9
Calcination with tin-— — 337
Exposed to strong fire with regulus of
antimony —- 359
with arsenic —--—-539
with zinc-361
Cupellatson with lead-561
with bismuth-— 373
Retains in cupellation some lead andbismuth, so as to prove brittle 56 tfreed from them and made malleableby continued strong sire — 3 68
limitations herein-— 372
Experiments of its greater affinity to one
metal than to another-377
of its greater or less affinity to acidsthan other metals have-381
Platina, means of distinguishing gold mix-ed with it-593, 597
o r purifying gold from it 591,595,399of extracting gold from large pro-portions of it-392
Its excellence for specula and other in-struments —- 576
Hints for forming it into malleable.
masses —- 372
Some metals improved and made moreserviceable by a small admixture of it-531, 536, 610
Poison-ajb, black juice from it-330
Raised in England—-— 331
Porctlaht,