Mr. C. Calvert on the Solubility of Sulphate of Baryta. 391 



What is not less useful to know is, that the solubility of sulphate 

 of baryta is affected in a higher degree by the bulk of the acid than 

 by its strength. The two following tables, taken from amongst 

 many others contained in the paper, will not only illustrate his fact, 

 but will also give an insight into the way in which the experiments 

 were conducted. The first table illustrates the influence which in- 

 creasing bulks of the same nitric acid exert on the formation of sul- 

 phate of baryta, and the second table the action which increasing 

 strengths of acid have : — 



Table XVI. 



Table II. 



These tables clearly show the influence which a given strength 

 of nitric acid has on the solubility of the sulphate of baryta ; for 

 there is a precipitate in three minutes in all the jars of the first 

 table, whilst we have a precipitate only in the first four jars of 

 Table II, 



Another fact which is observed in these tables is, that whilst 240 

 divisions of the alkalimeter of nitric acid, spec. grav. 1-167, are 

 capable of dissolving, or preventing the formation of, 4-46 grs. of 

 sulphate of baryta, 240 divisions of an acid, of spec. grav. 1-032, 

 only retained in solution 008G gr. It follows from these facts, that 



