February 17,1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
G61 
THE MICROSCOPE IN PHARMACY. 
BY HENRY POCKLINGTON. • 
(Continued from page 622.) 
The use of the microscope in the detection of 
adulterations would appear to date from a time not 
more remote than. 1850, when Dr. Hassall laid be¬ 
fore the Botanic Society of London This historic 
paper on the adulterations of coffee. Previously to 
the researches of Dr. Hassall and his collaborateurs 
on the Lancet Commission, it was commonly believed 
that, so far as many articles of common use were 
concerned, chemistry was utterly powerless to detect 
adulteration, and that it was vain to expect to be 
able to place any check upon the dishonesty or the 
malpractices of the vendors of those articles. So 
secure did the vendors of adulterated foods, drinks 
and drugs feel themselves, that the publication of 
Dr. Hassall’s reports was as if a thunderbolt had 
been thrown into their camp ; and to this day his 
papers exert a not unimportant influence for good. 
Although the practice of adulteration still exists to a 
frightful extent, and has become so respectable that 
a late member of the Government of this country has 
had the boldness to say that it is a mere species of 
“ competition,” and therefore perfectly allowable, yet 
it is not so prevalent with respect to articles com¬ 
monly used for food and drink as prior to 1850. 
Nor, so far as my experience goes, does adulteration 
take so dire a form now as before the publication of 
the Lancet reports. It is, at any rate, now possible, 
as I have proved again and again in my own house¬ 
hold, by dealing with respectable tradesmen, to pro¬ 
cure articles of more than “ commercial” purity. 
The present movement, in some of our large 
towns, for the appointment of a “ public analyst” is 
a sign of the times which members of the Pharma¬ 
ceutical Society will do well to take to mind. For 
there is little doubt that, with increased educational 
advantages, the common people will become more 
awake to the hygienic importance of pure air, pure 
water, and pure food; and that, before many years 
are passed, there will be found but few towns, or 
even large villages, without a duly-qualified public 
analyst, appointed and paid for by the ratepayers, 
for which post a member of the Pharmaceutical 
Society ought to be the most qualified person. With 
the idea that it may be useful to such a one, I shall 
include in these papers, not only notes on the detec¬ 
tion of adulteration in drugs, but also of foods, so 
far as the use of the microscope is specially advan¬ 
tageous. 
It may be best, perhaps, to make these articles a 
progressive course of instruction,—to regard first 
those substances which are most easily examined, 
and then to proceed, by as easy stages as possible, 
to those which require a more lengthened or difficult 
preparation before they can be microscopically exa¬ 
mined ; and we will wind up, if space permit, with a 
brief notice on the use of the microscope in the exa¬ 
mination of such things as sputa and urine, respect¬ 
ing which the opinion of a skilled microscopist is 
often required. 
W e will begin with the starches, arrowroots, and 
their allies, including “ foods ” and “ flours.” 
To become familiar with the microscopical appear¬ 
ance of the genuine article is obviously the easiest 
course to follow, if we merely wish to detect the pre¬ 
sence of an adulterant in arrowroot or any other 
Third Series, No. 8G. 
article. But, as in addition to its being of scarcely less 
importance to be able to pronounce what the adulte¬ 
rant is than to detect its presence, the procuring a 
well-authenticated specimen is a matter of great, 
and sometimes insuperable difficulty, when we have 
to deal with articles that are only imported in a 
“manufactured” condition, it is necessary to fami¬ 
liarize ourselves with the characters of all those 
substances which are likely to be used as adulterants. 
This will necessitate, in the case of arrowroots, etc., 
an acquaintance with the nature of starch, its origin, 
the resemblances and differences between the starches 
from different plants, and the nature of any inor¬ 
ganic or organic substances likely to be found in com¬ 
pany with starch naturally, or to be added as an 
adulterant. 
We are face to face with an analytic axiom,— 
that those substances only are used as adulterants, 
as a rule (which has, as may be expected, very few 
exceptions), that are less costly than the genuine 
article, and have characters sufficiently in common 
with it to enable them to pass muster, or will che¬ 
mically or mechanically enter into combination with 
it. These substances may be roughly subdivided 
into, those added to increase bulk or weight, and those 
added to blind the purchaser to faults of manufacture 
or inferiority of quality. 
Applying this axiom to the examination of arrow- 
root, we shall be led to test for cheaper starches, 
and, in the case of the higher-priced arrowroot, the 
presence of a lower-priced one. As a preliminary 
we shall familiarize ourselves with the microscopic 
appearance of such starches as are commonly found 
in commerce, and are sufficiently cheap to form an 
inducement to fraudulent men to make use of them 
for the purpose of adulteration. Foremost amongst 
these is starch from the potato. Potato-starch is so 
frequent an admixture with articles used in food, that 
it is very essential the analyst should make himself 
thoroughly familiar with it under all the circum¬ 
stances in which it can be placed. This is the more 
essential, because the microscopic appearances of a 
starch granule in situ , in water, dry, in oil, resin or 
spirit, raw and cooked by the aid of moist or dry 
heat, differ so widely that he who was acquainted 
with it under one condition only, would fail to recog¬ 
nize it under any of the others. The first thing to 
do is to procure the starch. It is so easily prepared 
from that not rare article, the potato, that it is not 
worth while to run the risk of being perplexed with 
an adulterated adulterant (a “ poisoned poison” is 
common enough) by examining the potato-starch of 
commerce. The simplest plan is to examine the 
granules in situ. Slice a potato into halves, and 
then cut as thin a section as possible with a sharp 
razor. Float this off on to a thin glass, add a drop 
of glycerine diluted with 25 per cent, of water, and, 
having covered it with a glass slip, proceed to exa¬ 
mine it with a half-inch or one-incli objective. The 
starch granules will be seen to lie loosely in the in¬ 
terior of large cells, and to vary greatly in size, from 
the fully-formed starch granules to. the exceedingly 
minute, almost shapeless granules tying along the 
centres of active growth. This wide range of form- 
element is exceedingly perplexing to the analyst of 
starches, and renders it excessively difficult in some 
cases to decide absolutely as to the precise nature of 
some of the starches submitted to him. But, although 
there is a wide range of size for each starch, yet each 
species lias a tolerably well-defined average, which 
