MOU), Ost | © Lormation of Microscopie Crystals. 215 
through the vascular walls does actually occur, is shown in one 
of the photographs which we are unable to reproduce. 
It will be seen from the foregoing details that, so far as the 
structure of the vascular walls and the passage of the white cor- 
puscles through them are concerned, the facts appear to be on the 
side of Cohnheim. How then with regard to the doctrine of inflam- 
mation which he builds upon these facts and upon his corneal 
studies ? Does the creeping out of the white corpuscles constitute 
the essence of the inflammatory process? Do these little movable 
masses of living protoplasm furnish the germs for the elements of 
new formations? Have pus-corpuscles no other origin? Are the 
processes which go on in the cells of the inflamed tissue purely 
passive, mere phenomena of retrograde metamorphosis ? 
I find the evidence insufficient as yet to afford satisfactory 
answers to such questions. The observations made by Cohnheim 
on the connective-tissue corpuscles of the tongue of the frog are 
not conclusive in themselves, and Stricker’s studies on the same 
subject * show the necessity of further labour in this direction before 
the possible multiplication of these elements in inflammation can 
be denied. As to the doctrine that the white corpuscles, after their 
escape from the blood-vessels, are transformed into the elements of 
normal or pathological tissues, the facts hitherto brought forward 
can scarcely be said to do more than raise it to the rank of an in- 
genious hypothesis. The actual steps of this transformation, if it 
does occur, have yet to be observed. 
In conclusion I may remark that, as the preparations referred 
to in this paper form a portion of the Microscopical Collection of 
the Museum, they can be examined by any professional microscopist 
who may visit that institution. [The specimens sent with the paper 
are in Dr. Maddox’s possession. | 
Army Mepicat Museum, 
MicroscoricaL SECTION, 
July 6th, 1870. 
V.—On the Formation of Microscopie Crystals in Closed Cells. 
By A. W. Wits. 
Puate LXIT. 
I pestRe to call the attention of microscopists to a mode of obtain- 
ing crystallizations of extreme brilliancy, which‘is, so far as I know, 
not commonly practised ; whereby, moreover, the very act of crystal- 
lization may be repeated an indefinite number of times upon the 
same minute quantity of material, and if necessary exhibited simul- 
* ¢Studien aus dem Institute fiir Experimentelle Pathologie in Wien aus dem 
Jahre, 1869.’ Wien, 1870. 
