PHYSIOLOGICAL TESTS FOR CERTAIN ORGANIC POISONS. 421 
nada, and in various barks of Ecuador and Peru, and markedly in the best of the barks 
of Loxa. It is highly probable that a very slight circumstance in the growth may deter¬ 
mine the production of one or other alkaloid. Dr. Herapath has Tpl 
cation to the Royal Society, “Researches on the Chinchona Alkaloids, ' that the 
quinine and chinchonidine salts agree closely among themselves, and differ widely ftom the, 
auinidine and chinchonine compounds. . 
I may further remark, that the Chinchona succirubra is a tree which varies greatly 
in its products in its native forests, and that the Chinchona micrantha, m Bolivia, ap¬ 
proaches to the character of a Calisaya , as I have noticed under that nead ; its bark has 
a different appearance from that of Huanuco, and, again, this now sent home vanes 
widely from either of the above. I notice, in examination, the peculiar yellow colour¬ 
ing-matter common, it seems, to all the forms of this species (C. micrantha ), as I have 
before noticed.^ ^ ^ ^ tim0 by Mr . M‘Ivor is, I fear, an illustration of the possi¬ 
bility of change in the wrong direction, as it contains far too large a percentage of c in- 
chonidine in proportion to the quinine. The appearance of the bark indicates a not 
very vigorous growth, or, at all events, it differs from that it assumes in its native 
locality. It would never be recognized as the bark of Chinchona, Calisaya. 
The bark of No. 6 is recognized by an experienced dealer as “ thin rusty crown worth 
1 q J tn 1 < id ner lb ”+ It is, I presume, the bark of the variety Bonplandia, i. e. 
IL MaddlZ as brought home by Cross; it is remarked as more red than rs cus- 
t0 As r th'equantitv of°ba”k in No. 1 and No. 4 was not exhausted in my experiments, 
I have returned 1000 grains of each of these, thinking that it would be a satisfaction to 
the Government to enfage Dr. De Vrij, whose chemical skill and knowledge are so well 
known, in further researches on the subject.-I have, etc. Howard. 
ON THE APPLICATION OF PHYSIOLOGICAL TESTS FOR CERTAIN 
ORGANIC POISONS, AND ESPECIALLY DIGITALINE. 
BY C, 
HILTON FAGGE, M.D., AND THOMAS STEVENSON, M.D. 
a a the chemical processes for the detection of certain organic poisons are very incon¬ 
clusive in their nature, and as many of these agents produce effects of a most rel ^ ar '‘ 
able kind on the lower animals, it is not surprising that their physiological action should 
have been employed as a test for their presence. Thus Dr. Marshall Hall suggested as 
a means of discovering strychnia, the tetanic symptoms which that alkaloid causes 
Ws and quite recently MM. Tardieu and Roussin produced a large mass of phy- 
LTogicarevidence, in a French cause celebre, in which digitaline was believed to be the 
P °Thosewho have recommended the employment of evidence of this nature have always 
relied on the similarity between the symptoms observed “‘ ““.nSwSto 
incr anrinp- life and the effects obtained m the lower animals by the extract Denevea to 
eontdn the toxiragent: and as the action of poisons on man and on the lower verte- 
bratals certainly nit always the same, the value of these physio ogical tests has been 
much disnuted and is not now admitted by most authorities in this country. It appears 
much aisputea, ana_ is nu eviden ce may be made independent of any relation of 
this kind We It’is^sufficient that the action of the substance believed to contain the poison 
this kind. It sumc e identical with the known effects of that poison upon 
of being produced by no other agent 
°^n\hBfmirit™eries°of investigations with reference to the de- 
to it at the present time, but also because t he 
I Pro* 'mLITjmuIis and Phillips to Mr. J. 7S. Howard.-* SI, Lime Street, 21st 
•TuWSeS.—The sample of bark you left with us appears to be thin rusty crown, no . 
Is. 3c?. to Is. 4c?. per lb. We thank you tor the sight oi it. 
