ANALYSIS OF SULPHATE OF BARYTES. J *J$ 



tained by Richter, Bucholz, Clayfield, and others I have 

 not particularly quoted, might have been supposed decisive 

 ef the question ; yet in a memoir on the composition of 

 alum, subsequent to that of Clement and Desormes on the 

 barytic salts, and posterior also to the laft experiments of 

 Klaproth, Messrs. Thenard and Roard have adopted the 

 proportion of 26 per cent of sulphuric acid in sulphate of 

 barytes, as the mean of the results obtained by one 6f them, 

 and those of Berthollet, after experiments conducted with 

 the greatest care. 



The question remaining still therefore undecided, and Occasion of 

 having myself engaged in a series of experiments on the Da pe r reSe0t 

 constitution and properties of the principal mordants em- 

 ployed in dyeing and calico printing, in which- 1 had fre- 

 quent occasion to ascertain the presence and quantities of 

 various sulphuric salts, I was under the neeeflity of satis- 

 fying myself respecting the composition of sulphate of ba- 

 rytes by direct experiments, the particulars of which form 

 the subject of this paper. 



On comparing the results of the different experiments on Comparatire 

 this subject, it will be seen, that, with the exception of results of for* 

 those of Thenard, Berthollet, and Chenevix, they a u meranal y**» 

 agree in stating the proportion of acid between 31 and 34 

 percent; the mean of the whole, and by far the greater 

 number, making it about 33. Klaproth, Cleme.it and 

 Desormes, an4 others, have deduced the composition of 

 sulphate of barytes, from that of the carbonate and ni- 

 trate ; and as this mode appeared to me at once simple 

 and unobjectionable, I followed it in the first instance 

 exactly. 



Carhoyate of Barytes, 



One hundred grains of carbonate of barytes were dis- Carbonate ©f 

 solved in dilute muriatic acid, with all the precautions ne- barytes dis- 

 cessary to prevent the dissipation of the solution, or loss r °Jic add?"*" 

 from too rapid disengagement of the carbonic acid. When 

 the effervescence ceased, the last portions of gas were ex- 

 pelled by a momentary exposure to heat. The loss 

 amounted to 21*65 grains. The experiment repeated on 

 5Q grains of the carbpnate gave 1Q*85 grains, or 21*7 per 



cent; 



! , 



