471 
» 
ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
(2) That the Microscope is of no value as a guide in the practice 
of medicine, because, aided by objective and subjective pathognomonic 
symptoms, and a few simple instruments and chemical tests, no scientific 
physician can possibly fail in diagnosing every known pathologic con- 
dition and change. The physical and chemical constitution of abnormal 
physiologic or pathologic animal products capable of poisoning the 
organism is as yet unknown, but as we have every reason to believe 
that they are alkaloidal in character, they, like all tbe known agents 
capable of sustaining the physiological or chemical activity of the 
organisms, are not visible to the Microscope. Comment is needless ! 
Red Blood-Corpuscles in Legal Medicine.* — Dr. M. C. White comes 
to the conclusion that, in favourable cases, blood-stains can be so treated 
that reliable measurements and credible diagnoses of their origin can be 
given. If error occurs on account of imperfect restoration of the form 
and diameter of the corpuscles, the error, if any, will be to make human 
blood appear like that of one of the lower animals, and will never lead 
to the blood of any domestic animal being mistaken for human blood. 
In general, when a stain has been proved to be blood it may be decided 
certainly whether it is or is not mammalian blood ; so also a stain 
from the blood of the ox, pig, horse, sheep, or goat may be distinguished 
from human blood, thus confirming the claim of an accused person in 
many cases that his clothes are not stained with human blood. This 
negative testimony is quite as important in many cases as testimony 
inculpating a prisoner. Lastly, the expert can say that the average of 
a suitable number of corpuscles from blood-stains corresponds with the 
average of fresh human corpuscles, that the stain is certainly not from 
the blood of the ox, pig, sheep, or goat, and, in every case, he can say with 
great certainty that the stain is not human blood. 
History of the Microscope.! — A very excellent and useful work 
on the history of the Microscope, from its first beginnings up to the 
present time. Since the last edition of Harting’s treatise in 1866, which 
contained the most complete resume of the development of the instrument 
up to the date of its publication, some, perhaps unavoidable, errors in 
facts and dates then extant have been corrected, and a good deal of 
supplementary information collected on the subject. Although this has, 
for the most part, been recorded in this Journal, it is convenient to have 
fhe information in a continuous form, as in the present work. The 
author lays no claim to have written an exhaustive or final history of 
the Microscope, but he observes that, while the modern instrument is 
generally fully described in microbiological literature, he finds so little 
■or even no mention made of its evolution, that he fears it may come to 
be overlooked. 
One other point may be mentioned in its favour : instead of the 
loosely stitched and paper-covered affair usually issued by Continental 
publishers, Dr. Petri’s work is extremely neatly half bound, with 
marbled edges, a new departure which, it is hoped, may be generally 
adopted abroad. 
* Medico-Legal Journal, xii. (1895) pp. 419-38 (12 pis.). 
f ‘ Das Mikroskop, von Dr. R. J. Petri.’ Berlin, 18§6, 248 pp., 191 figs, and 
2 facsimile portraits. 
2 k 2 
