58 
ANALYSIS OF POTABLE WATERS. 
into phosphoric acid and silver. This and the following experiments were made 
in a darkened room lighted only by gas. I followed the same process with 
“soluble phosphate,” made by removing two equivalents of the lime by sul¬ 
phuric acid; with hydrated phosphoric acid, made by nitric acid and phos¬ 
phorus ; with phosphorous acid, made by slow combustion; and triple phos¬ 
phate, “ microcosmic salt.” I next tried whether the natural textures of which 
the phosphate of lime formed a part gave the same indications, and sent to the 
butcher for some washed sheep’s intestines, and having cut some slips from 
them, went through the same process, and in every instance I produced the 
same black compound. 
It is evident, therefore, that this mode of proceeding must not be resorted to 
again in cases of toxicological inquiry. It has already been adduced in tw r o 
.cases of suspected murder. 
Your obedient servant, 
William Herapath, Sex., F.C.S., etc., 
Professor of Chemistry and Toxicology , Bristol Medical School. 
July 4 th, 1865. 
A DANGEROUS SUBSTITUTE FOR JALAP. 
Some serious and fatal accidents have recently occurred at Constantinople 
through the root of Aconite having been mistaken for Jalap. 
From what we can gather from the account of the occurrence given by Pro¬ 
fessor Dr. C. D. Schroff, of Vienna,* it would appear that a merchant at Con¬ 
stantinople received from Calcutta a parcel of a drug which he considered to be 
jalap, and which he sold as such to several apothecaries and druggists. This 
terrible error w r as soon followed by serious consequences. A fatal case of 
poisoning occurred, g,nd suspicions having been aroused respecting the medicine 
which the patient had taken, the danger was traced to the supposed jalap. A 
further examination revealed the fact that this drug was in reality aconite root, 
and of that peculiarly poisonous variety which is known in India as Bitch, and 
which is commonly attributed to Aconitum ferox , Wall., although the roots of 
other species are also collected under the same name. 
The confounding of drugs so little similar as jalap and aconite, seems, at first 
sight, to indicate extraordinary ignorance on the part of the purchasers. But 
we have found upon examination that some of the larger roots of the Indian 
aconite have a certain distant resemblance to the small and inferior jalap-tubers 
that have of late years appeared in the market. A very cursory examination, 
however, will immediately show their distinctness. 
OBSERVATIONS ON SOME POINTS IN THE ANALYSIS OF POTABLE 
WATERS. 
f 
BY PROFESSOR W. A. MILLER, M.D., LL.D., PRES. CIIEM. SOC., TREAS. AND V.P.R.S. 
(1.) Although the analysis of potable waters is an operation which every chemist has 
frequently occasion to perform, it is remarkable that there is much less agreement be¬ 
tween different operators in the exact mode of conducting the details of the analysis, 
and of reporting the results, than might have been expected. It is with the hope of 
contributing something towards facilitating greater uniformity in practice, and of add¬ 
ing precision to the results attained upon one or two important points, that I have been 
induced to bring the subject, trite as it may appear, before the Chemical Society on the 
present occasion. 
* Elne hochst gefahrliche Verwechslung der Jalapawurzel, in Zeitschrift cles altyemeinen 
Asterrcichischen Apotheker- Vereines, 16 Juni, 1865. 
