February 3, 1872.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
621 
THE MICROSCOPE IN PHARMACY.* 
BY HENRY POCKLINGTON. 
There is little doubt in my mind that so far as 
pharmacy is concerned the microscope is as yet in 
its infancy, but that it will at no distant date make 
a rapid stride towards an active and useful man¬ 
hood. The same might have been written a very few 
years since of the microscope in medicine, but it has 
ceased to be true lately, and is, thanks to the new 
regulations of the Royal College of Surgeons in 
England, not likely ever a^ain to be true. The 
utility of'the microscope in pharmacy, by which 
term I mean pharmaceutical science, not mere 
shop-keeping, is not, perhaps, so obvious as in the 
sister science of healing, but a little inspection will 
show abundant circumstances in which the micro¬ 
scope is not only of service, but indispensably so. 
I hope, in the course of my papers, to bring forward 
some cases in support of this proposition, and in 
doing so to afford to non-microscopists such infor¬ 
mation as may emible them, if the possessors of an 
instrument, to put it to immediate practical and 
technical uses. 
To meet the case of those, especially the students 
in provincial classes, who have not an instrument, 
but are intending to purchase, I have thought it 
advisable to give a few general hints as to the choice 
of a microscope suitable for the use of a pharmaceu¬ 
tical or medical student, and to add a few lessons in 
practical elementary microscopy; which hints ad¬ 
vanced students may skip if they choose. I am 
induced to write on this point, because I have 
lately found many who have deprived themselves of 
the assistance the microscope would afford, under 
the impression that no instrument likely to be of 
the slightest service could be purchased at anything 
like a reasonable cost. This might have been true 
a few years since, but it is so no longer. Any of our 
leading makers will supply a good useful micro¬ 
scope, with all necessary lenses and apparatus, at a 
cost not exceeding 4T0. The instrument I have 
nrgself used cost me some years since less than TO, 
and I am not disposed to throw it aside in favour 
of any more showy and costly stand. 
The essentials of a good working microscope may 
be very briefly summed up. The stand should be 
steady, and capable of being used vertically or ad¬ 
justed to any degree of slant up to the horizontal for 
drawing with the lucid a.. The stage must be roomy, 
very firm, and have a good aperture. The mirror 
should be large, and have a plane as well as a con¬ 
cave reflecting surface, and must be adjustable as 
regards focus, in addition to being capable of being 
thrown aside from the axis of the instrument for the 
purpose of oblique illumination. The lenses should 
give a clear flat field, and a power ranging from 20 
to 200 diameters ; and the height of the eye-piece 
from the table, \yhen a high power is used, should 
not exceed 10 or 12 inches. 
Such an instrument, with the addition of a polari- 
scope and fittings, will suffice for the ordinary work of 
either the pharmacist or the medical man, and may be 
purchased for Jcl of any of half-a-dozen good makers 
in town and country. There are so many makers 
whose instruments answer the requirements of stu- 
* The present article is introductory to a series of articles 
upon the use of the microscope in its application to pharmacy 
Third Series, No. 84. 
dents, and are sold within the limits we have given, 
that we hesitate to particularize any ; but in common 
justice I am bound to say that I have received from 
Messrs. Swift, of London, and "Winspear, of Hull, 
the utmost courtesy and assistance in my many 
microscopical emergencies. The latter maker has 
especially been always ready to carry into effect any 
economical “ dodge ” to which fancy or the force of 
circumstafices may have impelled me, and his 
“ Student ” strikes me as being so pre-eminently a 
student’s instrument, that it affords me much plea¬ 
sure to mention it in this place. I have seen and 
used the Student’s or other cheap instruments of 
Messrs. Beck, Wheeler, Collins and others, of 
London ; Dancer, of Manchester; and Husbands, of 
Bristol; and have no hesitation in recommending 
my readers to their very “ tender mercies,” in com¬ 
mon with the not less worthy brethren for whose 
names I have no space. 
In judging a microscope, the purchaser should see 
that the mechanical portions of the stand are well 
made, that the rack and pinion work smoothly, and 
the fine adjustment can be worked without throwing 
the object under view out of the field. This latter 
fault, known as “ twist,” is so excessively annoying, 
that its presence ought to secure the rejection of any 
stand, no matter how cheap or otherwise perfect. 
The stand should be firm, and the object should 
never “ dance ” under a moderate power, if even the 
table on which the instrument stands be shaken. 
The testing of the lenses is hardly possible to a 
beginner. He may, however, judge whether the 
margins of objects are seen with sharpness and 
absence of coloured fringes. The experienced mi- 
croscopist alone can form a just opinion of the 
quality of a reasonably good lens, and the beginner 
should, therefore, either go to a good and established 
maker, or get the advice of a competent person be¬ 
fore purchasing. 
I have recently, in these columns, given a “ Chapter 
on Microscopy,” in which were some general direc¬ 
tions as to the use of the microscope with regard to 
choice of light and position, avoidance of errors of 
interpretation and the like, and to it I must refer 
my readers for information upon those points. In 
that article I spoke of the “ lumps of sugar ” blunder 
in microscopy. This blunder, in one form or other, 
so largely obtains, that I will address myself at 
once to the consideration of the right way of using 
i the microscope for the examination of animal, vege¬ 
table or mineral substances. 
Those objects that do not require preparation .— 
These are, apart from “mounted slides,” the reverse 
, of numerous, and will almost all of them require to 
! be viewed as opaque objects by reflected light. The 
use of reflected light is only admissible with low 
powers, unless special apparatus be made use of, 
j and does not require much explanation. A “ bull’s 
eye” condenser is generally used to increase the 
amount of light reflected by the object under exami¬ 
nation, and the adjustments of this do not possess a 
very wide range. The beginner should bear in 
mind that too much light is worse than too little, 
and should contrive that a larger field is illuminated 
than can possibly be occupied by the lens. The 
reason of this is, that the better portion of the con¬ 
denser alone may be made use of, and that the 
peripheral portions of the impinging cone, usually 
coloured from the want of achromatism of the con¬ 
denser, may not enter the objective. Usually, but 
