468 
ORIGINAL AND EXTRACTED ARTICLES. 
ON MR. WOOD’S PAPER UPON “ LIQUOR BISMUTHI ET 
AMMONIA CITRATIS.” 
BY Gr. F. SCIIACHT, CLIFTON. 
In an article published in last month’s Journal, Mr. C. H. Wood, F.C.S., 
takes occasion to contradict the assertions contained in a late advertisement of 
mine, in which I endeavoured to point out the differences likely to occur be¬ 
tween the u Liquor Bismuthi et Ammonise Citratis” as found in commerce, and 
the u Liquor Bismuthi (Schacht),” which it was intended to imitate, and 
deplored that a name so closely resembling the original should have been selected 
by the compilers of the Pharmacopoeia. 
It is somewhat unusual to find a business advertisement made the text for a 
scientific essay. I admit I have no cause of complaint in respect of the tone in 
which allusion is made to myself and my preparation, which indeed is sufficiently 
courteous, but in the very nature of things a scientific writer holds an adver¬ 
tiser, for the time at least, at an unfair advantage. The aim of the advertiser, 
for many reasons, is to be as brief as possible ; hence he takes no notice 
of correlative facts, nor of the possible exceptions to the broad statements he 
affirms. He is addressing himself, most probably, to a commercial question, and 
occupies himself only with its commercial illustrations. 
Such, at least, was my idea in framing the particular advertisement in ques¬ 
tion, and, to the best of my knowledge, its statements are in this sense perfectly 
true. I never meant to assert that it was impossible for Mr. Wood or any 
other experimentalist to make a “ liquor bismuthi et ammonise citratis ” free 
from copper, arsenic, and antimony, by the Pharmacopoeia process, for I knew 
that samples of metallic bismuth might be found in museums and scientific 
collections free from these contaminations ; but I also knew not only that such 
pure samples are rare, but that very few commercial samples couki be found 
which it would be possible to render pure by the Pharmacopoeia process. I 
therefore argued that manufacturers would be little likely to employ this im¬ 
perfect and wasteful process (as I shall presently prove it to be) of purification, 
but would most probably proceed in their preparation of this liquid bismuth as 
they have hitherto manufactured the trisnitrate, and would consequently pro¬ 
duce an article such as my advertisement described. 
But Mr. Wood disputes my assertions on scientific grounds ; let us see, even 
from this point of view, how far he is justified in so doing. 
I state, in the first place, that the Pharmacopoeia preparation will contain 
nitric acid. As he cannot in any way deny this, Mr. Wood says, “ no doubt 
the authors of the process thought its presence would do no harm, or they would 
have taken means to exclude it.” To this I reply, they could not possib'y have 
excluded it, except by modifying the whole process ; and, moreover, that my 
advertisement makes no allusion to the harm it would do, nor, indeed, to the 
harm the copper or arsenic would do if present,—it merely points out, that in 
every pound of the preparation about two ounces of nitric acid is retained ; and 
this Mr. Wood is bound to admit. So my first commercial statement is scien¬ 
tifically correct. 
My next is, that it will almost invariably contain copper. This is met by 
Mr. Wood in a counter-assertion, that if the metal be purified by the Pharma¬ 
copoeia process the copper will be removed. I hope I am not misstating Mr. 
'Wood’s position. I think it clear he means this, for he says “ he found in one 
