IMIDOSTJLPHONATES (2ND. PAPER). 207 



However, while he had two products to select from, we must now say 

 that we had not, and still have not, always getting one and the same 

 ha sic mercuric salt. 



To make sure that we had not heen mistaken, and therefore that 

 Berçdund's finding could not he confirmed, we have made further 

 experiments, — in one of them following him as closely as possible, in 

 others striving by means of more acid solutions to reduce the basicity of 

 our precipitates to that of his. But, before stating these experiments 

 and their results, we have two adverse comments to make upon those 

 reported by Berglund. 



One is as to the precipitation of mercuric oxide or basic nitrate 

 inferred by him. However prepared, our product has always been one 

 of the whitest of precipitates, only assuming a faint buff tint when 

 kept for some time at 100° or higher in the dry state. The presence 

 of very little oxide or basic nitrate should have shown itself 

 by a yellowish colour. No precipitate we have tested of the 

 present salt, of the oxymercuric sodium salt (6, 105), of the 

 mercurous salt (this paper, p. 212), or of the mercurosic salts (this 

 paper, p. 214), has ever shown the presence of nitric acid in it. 

 Nor can Berglund's supposition, that mercuric oxide or basic nitrate 

 might be precipitated, be adopted as probable, when it is considered 

 that the mother-liquor of the precipitating salt is much more strongly 

 acid than the solution of mercuric nitrate used. 



The other matter to be pointed out is the unlikelihood of mercury 

 taking or retaining the imidic relation in a salt precipitating from such 

 very acid mother-liquors ; since, as we have shown in our first paper, 

 dilute nitric acid replaces such mercury by hydrogen. Berglund 

 thought this not to be the case, but it is so nevertheless. Now, 



o 



directly the attempt is made to lessen the quantity of nitric acid 

 enouo-h to let mercury take the imidic relation, sodium or potassium also 



