ASSAYING. 



corification, in proportion to the increase ty of lead, required for the same weight, 

 of alloy, shown by the decreasing quanti- of copper, under different mixtures. 



Silver. Copper. 

 23 with 1 requires 



Silver. 



22 



20 



18 



16 



14 



12 



10 



8 



6 



4 



2 



2 

 4 

 6 

 8 

 10 

 12 

 14 

 16 

 18 

 20 

 22 



Lead. Ratio of Inc. Copper- 



96 = 4 X 24 and hence 



144 == 6 X 24 1 ... 11 



192 = 8 X 24 1 ... 5 . 



240 = 10 X 24 1 ... 3 . 



288 = 12 X 24 1 ... 2 . 



336 = 14 X 24 1 ... 11 



384 = 16 X 24 1 ... 1* 



432 = 18 X 24 1 ... T 



480 = 20 X 24 1 ... 



528 = 22 x 24 1 ... 4 



576 = 24 X 24 1 ... i 



624 = 26 x 24 1 ... f 



iT 



1 with 23 requires 95 * 



. ;7 



. 48 



. 40 



. 36 



. 33 



. 32 



. 30 x 



. 30 



29 X 



. 28 X 



. 28 X 



It should be remarked, however, that 

 many assayers, of good authority, use 

 proportions of lead to alloy, considerably 

 different from the above table ; and that 

 the whole numbers here given may be 

 considered as rather high in proportion to 

 the quantity of lead. 



The proportions of lead for gold assay- 

 ing are nearly the same as for silver. 



Assays of alloys with platina are con- 

 ducted nearly in the same manner as for 

 the mixtures of silver and gold. Silver 

 is seldom alloyed with it ; but gold is more 

 frequently ; and is known by the much 

 greater heat it requires in the fusion ; by 

 the edges of the button appearing thicker 

 and rounder than in common assays of 

 gold ; by its colour being duller, and tend- 

 ing to yellow; and its being entirely 

 crystallised on its surface. 



The action of nitrous acids on the alloys 

 of platina is very remarkable. By itself, 

 platina is as insoluble in this acid as gold, 

 and a mixture of these two metals equally 

 resists its action ; but when silver enters 

 into the mixture, in the proportion of 2, 

 or three times the weight of the gold and 

 platina, and when the platina is not above 

 a tenth of the gold, the platina is totally 

 soluble in nitrous acid, together with the 

 silver, and the gold alone remains un- 

 touched. 



When the gold mixed with platina is 

 to be freed from it in the above manner, 

 it must be laminated very thin; a weak 

 acid is first added, and boiled for some 

 time. If the platina is above two per 

 cent, of the gold, the acid assumes a straw 

 colour, which deepens in proportion to 

 the platina, and at the same time the cor- 

 nets assume a brownish green. A strong- 

 er acid is then added, and boiled three 

 times successively, to detach the last por- 

 tions of platina, which are separated with 



VOL. 11;. 



difficulty . By laminating very fine, u-ing 

 the acid liberally, and long boiling, all 

 the platina may be separated in one ope- 

 ration, when it does not exceed a tenth 

 of the gold: and above that proportion, 

 the colour of the gold is so much debased, 

 and the appearances on the cupel so 

 striking, that fraud can hardly escape an 

 experienced eye. Parting might be used, 

 even when the platina was more than a 

 tenth of the gold, but then more silver 

 must be added, which would render the 

 cornet so very thin, after the action of the 

 acid, that it could hardly be annealed with- 

 out breaking. 



When alloys of silver alone with platina 

 are treated with nitrous acid, the silver 

 dissolves as usual, but the liquor soon 

 becomes muddy, with a very fine bulky 

 black precipitate, which continues in- 

 creasing till all the silver is dissolved, and 

 which is found to be entirely platina when 

 collected A part of the platina, how- 

 ever, remains in the solution ; for, on add- 

 ing muriatic acid to the liquor separated 

 from the black precipitate, white lima 

 cornea falls down, after which carbonate 

 of potash will throw down a green coagu- 

 lum, which is oxide of platina. The above 

 effects of nitrous acid will therefore de- 

 tect an alloy of silver and platina. 



ASSETS, are goods or property in the 

 hands of a person, with which he is ena- 

 bled to discharge an obligation imposed 

 upon him by another; they may be either 

 real or personal. Where a person holds 

 lands in fee-simple, and dies seized there- 

 of, those lands, when they come to the 

 heir, are called assets. So far as obliga- 

 tions are left on the part of the deceased 

 to be fulfilled, they are called assets real. 

 When such assets fall into the manage- 

 ment of executors, they are called assets 

 intermaincs, When the property left 



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