206 Histology of Minute Blood-vessels. [Wottnd Oct. 10. 
since the publication of the paper of Dr. J. Cohnheim,* on inflam- 
mation and suppuration. 
Perhaps the observations of Cohnheim must fairly be regarded 
as elaborations of the previous experiments of Dr. Augustus Waller, 
but certainly they produced an impression upon the medical world 
far beyond that made by the papers in the ‘ Philosophical Magazine,’t 
and more or less complete accounts of the conclusions arrived at by 
the distinguished Berlin observer have continued to appear, from 
time to time, in both foreign and American medical journals, ever 
since the publication of his paper in 1867. 
Recently protests against these conclusions have appeared in 
various quarters, among which particular reference may be made to 
the paper of Prof. Koloman Balogh, of Pesth, published in 1869,t 
and that of Dr. V. Feltz, of Strasbourg, in 1870.§ Both these 
authors have failed to see the white blood-corpuscles pass through 
the coats of the small vessels in the manner described by Cohnheim, 
and deny the existence of stomata, between the cells of the vascular 
epithelium, large enough to permit such a wandering to occur. 
After I had perused Cohnheim’s paper I procured a number of 
frogs, and having on hand a small quantity of Wourara, the gift 
of my friend Dr. §. Weir Mitchell, of Philadelphia, I carefully 
repeated many of the experiments described. I received the impres- 
sion from what I saw that Cohnheim was a most conscientious 
observer, who had described as faithfully as possible the impressions 
made upon him. Certainly the results I obtained, by following his 
methods of producing inflammation in the cornea and mesentery of 
frogs, could be described in his very language without drawing upon 
the imagination. Nevertheless my other duties did not leave me 
sufficient time for an exhaustive research in this difficult domain, and 
it is far from my present purpose to enter into a critical discussion 
of the subject. It is simply my desire to offer a brief description, 
illustrated, of certain preparations in the Microscopical Section of 
the Museum, which bear upon some of the points involved, and thus 
to contribute what is in my power towards the important object of 
* “Ueber Entziindung und Eiterung,” Virchow’s ‘ Archiv,’ Bd. XL., S. 1. 
+ ‘“ Microscopical Examination of some of the principal Tissues of the Animal 
Frame as observed in the Tongue of the Living Frog, Toad, &c.,” ‘ London, Edin- 
burgh, and Dublin Philosophical Magazine,’ vol. xxix., p. 271 (1846). ‘‘ Micro- 
scopical Observations on the Perforation of the Capillaries by the Corpuscles of 
the Blood, and on the Origin of Mucous and Pus Globules,” ibid., p. 397. 
t ‘‘In welchem Verhiltnisse steht das Heraustreten der farblosen Blutzellen 
durch die unversehrten Gefasswandungen zu der Entziindung und Hiterung?” 
Virchow’s ‘ Archiv,’ Bd. XLV., 8.19. Readers inclined to attach importance to 
this paper should read the caustic criticism of Dr. Alexis Schklarewski of Moscow, 
ibid., Bd. XLVL., 8. 116. 
§ “Recherches Expérimentales sur le passage des Leucocytes 4 travers les 
pore eee ‘Journal de l’Anatomie et de la Physiologie, Jan. and Feb. 
> P. 9. 
