/ 
to Mr* kir wan’s Experiments and Qbftrvations on 
will be freed from its acid and calomel formed, i margraaf 
.284. ; and yet, if calomel and fllver be diftilled, the mercury 
will pals in its metallic form, and horn filver will be formed, 
ibid. 2 >6. The fame thing happens if fiver and fublimate 
corrofive be diftilled, 1 pott. 338. stahl des Jels, 306 ; the 
affinity of calx of mercury to phlogifton increafng with the 
heat. 
Of precipitations of and by bifnuth. 
With refpeCt to the vitriolic acid I have made the fum of the 
quiefeent and divellent powers equal, though in fa£t fome- 
times the one preponderates and fometimes the other. Wif* 
muth precipitates nothing from vitriol of copper in 1 6 hours ; 
nor does copper from vitriol of wifmuth. Copper is faid to 
precipitate wifmuth from the nitrous acid ; but 1 have alfo feen 
copper precipitated from this in its metallic form by wifmuth. 
The variations proceed from the different dephlogiftication of 
copper. 
Of precipitations of and by nickel. 
Unlefs nickel be pulverifed it fcarcely precipitates any metal. 
Zinc precipitates a black powder from the folution of nickel 
in the vitriolic and nitrous acid, which Mr. bergman, by a 
method peculiar to him, has fhewn to confift of arfenic, nickel, 
and a little of the zinc itfelf. The arfenic attracting the calx- 
of nickel * ; but zinc precipitates nickel from the marine acid. 
The folution of iron in vitriolic acid aCts on nickel, and’ 
that of nickel in this fame acid aCts on iron ; but neither pre- 
cipitates the other in 24 hours ; but on longer reft, iron feems- 
to have the advantage ; but iron clearly precipitates nickel 
* 1 suepisk, Handling. 1780. 
T 
from 
