1825.'} Mr. Phillips's Reply to Mr. Whipple. 55 



of acid are removed by lime, I will admit that only three-fourths 

 of it are obtained in the state of pure sulphate of potash, the 

 cost of which will be 20/. per ton. 



In making these statements, I suppose the trouble and 

 expense of the operations to be equal. 



The remarks next requiring observation are separated by a 

 paragraph which I shall presently notice : they are, " Moreover 

 I would ask, since economy be the maximum on which he has 

 founded his examination, whether this salt could not be more 

 economically obtained by employing potash in the process for 

 forming the ferrum praecipilatum ;" and " My remark relative 

 to the ferri subcarbonas, will be seen in the note on sulphate of 

 potash." It is to be observed that the College directs subcar- 

 bonate of soda for the decomposition of sulphate of iron in the 

 preparation of what they term Jerri subcarbonas, and Mr. W. 

 calls ferrum pracipitatum. I have repeatedly endeavoured to 

 obtain this compound by using subcarbonate of potash instead 

 of soda, but from some unexplained cause, the carbonate of iron 

 never contained so large a proportion of carbonic acid in the 

 former case. I do not suppose that the carbonic acid has any 

 immediate good effect, but when combined with protoxide of iron, 

 it prevents its becoming peroxide, and consequently retains it 

 in a more soluble state. 



Mr. Whipple's next observations apply to what I have stated 

 respecting the preparations of iron. " To attempt a definition 

 of his remark on the preparations of iron, would be Aquam 

 arare, wherefore I shall be obliged, if favoured with information, 

 as to its abstract tendency. What must be the inference of an 

 assertion like the follov/ing? ' That in the preparations of iron, 

 there have been some alterations which are to be considered as 

 amendments ; but I am apprehensive that the good zchich has been 

 done is more than counterbalanced bi/ the omission of improvements, 

 or the commission of errors.' Surely, if in the formuliie, that is, 

 such as have been altered, amendments have taken place, how 

 can we ascril)e to the College a want of ability, or the commis- 

 sion of error?" I trust that most persons would understand 

 that I conceive the College to have done some good, and more 

 harm — the harm being of two kinds ; positivehy the commission 

 of errors, and ncj^^nlive by the omission of improvements. I will 

 give instances of each : the process for preparing Ferrum tartar- 

 izatum is improved ; Vinum ferri is rendered worse by depriving 

 a weak preparation of nearly one-third its strength. In the direc- 

 tions for preparing-yenvz/M aminoniatum, about one-third only of 

 the subcarbonate of iron ordered to be used are dissolved by the 

 muriatic acid, and by the alterations introduced not only is waste 

 incurred, but the apparent strength of the preparation is nuich 

 greater than its real power. With respect to the omission of im- 

 provements, it is to be observed that more than one-fourth of the 



