VOL XC.] PHILOSOPHICAL TRANSACTIONS. 650, 



silver, in § 11th. These 48.5 gr. were proved to be chiefly oxalate of lime ; but 

 they contained also a minute inseparable quantity of mercury, almost in the state of 

 quicksilver, formerly part of the 84 gr. from which they were separated. Had the 

 48.5 gr. been pure calcareous oxalate, the quantity of pure oxalic acid in them 

 would, according to Bergmann,* be 23.28 gr. Hence, by omitting the 2 gr. of 

 mercury in the 3.4 gr. of carbonate, 100 gr. of the mercurial powder might have 

 been said to contain, of pure oxalic acid 23.28 gr. ; of mercury 62.72 gr. ; and of 

 nitrous etherized gas and excess of oxygen 14 gr. But, as the 48.5 gr. were not 

 pure oxalate, inasmuch as they contained the mercury they received from the 84 

 gr. from which they were generated by the nitrate of lime, some allowance must be 

 made for the mercury successively intermixed with the 84 gr. and the 48.5 gr. 



In order to make corresponding numbers, and allow for unavoidable errors, I 

 shall estimate the quantity of that mercury to have amounted to 2 gr. which I must 

 of course deduct from the 23.28 gr. of oxalic acid. I shall then have the following 

 statement : 



That 100 gr. of the fulminating mercury ought to contain, of pure oxalic acid 21.28 gr. 



Of mercury formerly united to the oxalic acid 6*0.72 



Of mercury dissolved in the sulphuric liquor 2 



And of mercury left in the sulphuric liquor after the separation of the gases 2 



Total of mercury 6*4.72 



Of nitrous etherized gas and excess of oxygen 14. 



100. 



Since 100 gr. of the powder seem to contain 64.72 gr. of mercury, it will be im- 

 mediately inquired, what becomes of 100 gr. of quicksilver, when treated as directed, 

 in the description of the process for preparing the fulminating mercury. It has 

 been stated, in § 9, that 100 gr. of quicksilver produce, under different circum- 

 stances, from 120 to 132 gr. of mercurial powder; and, if 100 gr. of this powder 

 contain 64.72 gr. 120 gr. or 132 gr. must, by parity of reasoning, contain 78.06 

 gr. or 85.47 gr. ; therefore 13.34 gr. or 20.75 gr. more of the 100 gr. are immedi- 

 ately accounted for; because 64.72 gr. -J- 13.34 gr. = 78.06, and 64.72 gr. + 

 20.75 gr. = 85.47 gr. The remaining deficiency of 21. 94 gr. or 14.53 gr. which 

 with the 78.06 gr. or 85.47 gr. would complete the original 100 gr. of quicksilver, 

 remains partly in the liquor from which the powder is separated, and is partly 

 volatilized in the white dense fumes, which in the beginning of this paper I com- 

 pared to the liquor fumans of Libavius. The mercury cannot, in either instance, 

 be obtained in a form immediately indicative of its quantity ; and a series of experi- 

 ments to ascertain the quantities in which many different substances can combine 

 with mercury, is not my present object. After observing, that the mercury left in 

 the residuary liquor can be precipitated in a very subtle dark powder, by carbonate 

 of potash, I shall content myself with examining the nature of the white fumes. 

 * Bergmann, de Acido Sacchari. Opuscula. torn. 1, $ 6. p. 248. Leipzig, 1788. — Orig. 



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