456 
ON THE ANATOMY OF DEUGS. 
of structural affinity, and so on to larger and larger groups. Thus it will be 
seen that there resides in the properly conducted study of the peculiarities of 
structure a means of identification, and of course this will include facility of de¬ 
tection in case of sophisticated or adulterated samples. Indications of the age 
of many vegetable products, and of their suitability for use in medicine, and in 
some instances even assistance in the determination of their medicinal value, 
may be obtained by microscopic examination. Again, it is in the internal ana¬ 
tomy of drugs that we find the key to their external appearances on which 
market value so often depends. These are considerations which the most prac¬ 
tical man will scarcely overlook. But there is a higher wisdom in the endeavour 
to derive interest from the objects that lie nearest to us, and with which we are 
necessarily brought in contact daily and hourly, and it is on this ground that 
we would put in a plea for the microscope. 
In a former paper we dealt with history rather than scientific details. The 
object in doing so was twofold,—firstly, to do justice to a few of the older 
microscopists, to wdiose labours we owe our earliest items of knowledge of the 
subject; and, secondly, to show how gradually the facts, which formed the basis 
of subsequent more systematic study, had been collected. At the commence¬ 
ment of the present century not less than fifty vegetable substances used in 
medicine had been examined by microscopists, and their structural peculiarities 
more or less completely described, and since that time almost every writer on 
Materia Medica has added some result, small or large, from his own investiga¬ 
tions ; we propose, therefore, now to give an outline of the present state of our 
knowledge, based upon the ‘Atlas’ compiled by the late Dr. Berg, of Berlin. 
But before we do so, it may not be out of place to express the regret with 
which w’e have heard, since the greater part of our paper was written, of the 
death of the author whose work we were in the act of reviewing. He had been 
long out of health, and pharmaceutical science loses in him a diligent and 
laborious student, as his many works on pharmaceutical botany and the organic 
portions of Materia Medica testify. We have thought it best to allow the criti¬ 
cisms to stand as they were w^ritten, knowing that our readers will accept the 
endeavour to come at the truth without prejudice to his memory. It would be 
surprising, indeed, if in the large amount of work Professor Berg w’as engaged 
upon, it were all to be found of the same degree of accuracy and completeness. 
Plates naturally form the most important part of a treatise on any subject in 
which the microscope is employed, for mere verbal descriptions avail little by 
themselves, to carry home an author’s meaning. Microscopical drawings may 
be said to be of two sorts, those which represent objects as they actually appear 
under the microscope, and those which give, as it were, an ideal diagram from 
which the real structure may be inferred. Each has its advantages, but we may 
be excused a preference for the former mode, the one usually practised in this 
country. However thin a section may be, a drawing of it requires some shading 
accurately to represent the object, and in many cases the thinnest sections are 
not the most characteristic. On the other hand, the more mechanical plan is 
sometimes less liable to confusion, and admits of special characters being made 
more conspicuous. The reader will often understand the author’s meaniug 
more readily, but is apt to be disappointed when he comes to examine the struc¬ 
ture under his own microscope, and at first may be unable to identify the 
various portions he has seen so strikingly figured. Dr. Berg’s plates belong to 
this latter class, and are the best of the sort; they are so good, that after we 
are once accustomed to his somewhat unnaturally hard lines, we cease to wish 
to see them altered. 
Acotyledoxs. — Thallogens .—But very few simple cellular plants seem to 
be possessed of qualities serviceable in medicine. Amongst the Fungi we still 
