1821.] Mr. Phillips's Reply to Dr. Hope. 19" 



Article V. 



A Reply to Dr. Hope's " Remarks on Mr. Phillips's A/iali/sis of 

 the Pharmacopeia Collegii Regii Medicorum Ed'ndmrgoisis.* 

 By R. Phillips, FRSE. &c. 



SIR, 



In the latter part of your remarks upon my analysis, yoir 

 *' earnestly beg " that I will " take the trouble of repeating those 

 processes " of your Pharmacopoeia to which I objected. I have 

 complied with your wish in this respect, and if I mistake not, the 

 results are not such as you anticipated. I acknowledge now 

 generally, and shali as I proceed more particularly, state some 

 errors which I committed in my analysis ; but I confess I am 

 not a little surprised that you should complain of the tone of my 

 observations. Of yourself I spoke with the respect which I felt, 

 but I trust that I never shall shrink from expressing my opinion 

 of a public performance, on account of any respect for the indi- 

 viduals who may have had a share in its production. I might 

 have stated my objections in more words, but I prefer brevity ; 

 and as I am not aware of the cause of your complaint, I shall 

 pursue the same plan in my reply, as I did in what you term my 

 attack. 



The first directions to which I shall refer are those for prepar- 

 ing the acidum aceticum forte. To these I objected, " that the 

 quantities of the salts employed are not such as are required for 

 mutual decomposition." In your remarks, you say, " the object 

 of this process is to obtain a very strong acid capable of dissolv- 

 ing camphor at a cheaper rate than from acetate of copper." 



Before I make any other observation, I must confess that the 

 acetic acid which I have obtained by frequently repeating your 

 process is very much stronger than that which 1 at first pro- 

 cured ; the extreme slowness of the distillation leading me 

 to conclude that it was nearly or quite over, before I had 

 obtained the whole of the acid. 



The process for preparing acetic acid, it will be proper to 

 state, for the information of the reader; it consists in decomposing 

 10 ounces of acetate of lead by 12 ounces of sulphate of iron 

 dried to whiteness. In order to determine the comparative cost 

 of preparing the acid by this process, and by that of the decom- 

 position of acetate of copper, which you consider as more 

 expensive, it will be requisite to state the composition and value 

 of the different substances employed in each method. 



According to Dr. Wollaston's scale, crystallized sulphate of 

 iron consists of 



* See Annals of Philosophy for January and March last. 



c2 



