286 



Art. IX. On the Atomic Weight of Silver, and on the 

 Constitution of Liquid Muriatic Acid at different Densi- 

 ties; 6j/ Andrew Ure, M.D., F.R.S., Professor of the 

 Andersonian Institution at Glasgow, M. G. S., S^c. 



[This paper forms the introduction to an elaborate Memoir on the nature 

 and manufacture of Chloride (Oxymuviate) of Lime, and on the atomic 

 weights of Silver and Manganese, with which we have been favoured by 

 Dr. Ure, and which will appear in our next Numl)er.] 



Upwards of four years ago, I published an account of a set 

 of experiments, which I had made on the saturating power of 

 liquid muriatic acid of 1.102, with a table of its progressive 

 densities, and corresponding acid strengths. This table was 

 favourably received by the chemical world, and has since been 

 adopted into most of our respectable treatises on Chemistry. 

 Having had occasion last spring to subject muriatic acid in 

 different states of dilution, to a very rigorous examination, I 

 perceived small deviations in the new results, from my former 

 tabular quantities, which induced me to revise the whole with 

 the greatest possible care *. My first business, however, was 

 to settle the prime equivalent or atomic weight of silver. For 

 this purpose I revived from the washed chloride of this metal a 

 portion of silver which I re-dissolved in pure nitric acid, fil- 

 tered the solution, re-produced the chloride, and once more 

 revived the silver by ignition with pure carbonate of potash. 

 The metal being well boiled in distilled water, washed, and 

 dried, I regarded as perfectly pure, and dissolved a known 

 weight of it in a sufficient quantity of nitric acid. The solution 

 was then diluted with water, so that the silver formed one- 

 twentieth of the whole. I next dissolved, in some of the same 

 double distilled water, 75 grains of pure sal gem, (native muriate 

 of soda, which stood the tests of muriate of barytes and oxalate, 

 and phosphate cf ammonia,) and mixed with that solution one 

 of the nitrate of silver, containing 137.5 grains of metal. Gentle 



* Subsequent researches have not enabled me to make any improve- 

 ment on my tables of Sulphuric and Nitric Acids. I believe them to be 

 very near the truth. 



