64 Mr. Phillips's Reply to Mr. Whipple. [Jan. 



least congratulate himself upon his consistency, for his matter is 

 worthy of his style. 



The part of Mr. Whipple's letter which I shall first notice is 

 the following : " 1 should esteem it an obligation, if favoured 

 with a translation of the first nineteen lines of the paper, the 

 parvum in iniilro." These hues I do not think it necessary to 

 repeat, but their meaning is, in my opinion, so obvious, that I 

 have no words to render it more so ; I am, therefore, compelled 

 to leave the reader to decide, wliether I write sense, or Mr. 

 Whipple cannot understand it. 



"On the formula for the preparation of sulphate of potash," says 

 Mr. W. "the writer of the paper is most fatally mistaken. In my 

 opinion, the College have acted most judiciously in directing that 

 the excess of acid be saturated with potash, instead of lime, for, in 

 this instance, they employ a salt of a very inferior value to 

 obtain one of a greater (and, by the bye, of some considerable 

 importance to. every manufacturing chemist), and, therefore, 

 contrary to the opinion of the writer (of that paper), \\ho says, 

 " The College would have acted economically in imitating the 

 directions of the Edinburgh Pharmacopoeia, by saturating the 

 excess of acid of the bisulphate, with lime instead of potash ; by 

 this the waste would have been avoidedof using a salt of greater 

 value to obtain one of less." A single importunity to any of the 

 drug warehouses will convince him of his eiror." This case is 

 very easily settled, and I shall make great allowances in Mr. 

 AV.'s favour, and yet the result will be in mine. Having made 

 more than " a single importunity " to the requisite sources of 

 information, I will admit that sulphate of potash is sold at a 

 higher price than the subcarbonate ; and this fact I may fairly 

 claim as favourable to the accuracy of my statement; for the 

 high price of the sulphate is the natural result of expensive 

 means employed for its preparation. 



The circumstances of the case are these : the College directs 

 nitric acid to be procured by decomposing nitrate of potash 

 with an equal weight of sulphuric acid ; the residuum is conse- 

 quently bisulphate of potash composed of 88 sulphate of potash 

 and 40 dry sulphuric acid. The question, therefore, is, whether 

 it is more economical to reject those 40 parts of dry sulphuric 

 acid after saturation with lime, or to convert them into sulphate 

 of potash by employing the subcarbonate. 



Pearlash is impure subcarbonate of potash, but I will suppose 

 it to be pure; it is sold at about 44/. per ton ; 40 parts of dry 

 sulphuric acid require 70 of it for saturation; 22 of carbonic 

 acid are expelled, and 88 of sulphate of potash produced. A 

 short calculation will show that the cost of a ton of it thus pre- 

 pared will be 35/. 



Impure sulphate of potash is readily procurable in the market 

 for about 15/. per ton, and when the impurities and slight excess 



