FIBRINOUS FLAKES. 193 



reference has already been made, and which have been termed 

 fibrinous flakes. With regard to the latter, their name indicates 

 that their discoverer, H. Nasse,* considers these irregular, crum- 

 pled and indented plates, which at most have a diameter of T ^o'" 5 

 as a peculiar form of coagulated fibrin, a view to which Virchowf 

 has recently given in his adhesion, but which is opposed by the 

 observations of Henle, DoderleinJ and Zimmermann, who found 

 these flakes in uncoagulated blood (both in the fresh fluid and in 

 blood whose coagulation had been impeded by the addition of 

 salts). Hence this substance would necessarily constitute a 

 perfectly distinct variety of fibrin, and therefore a substance which 

 is not fibrin : we have, however, already seen (in vol. i.) that fibrin 

 itself has never been exhibited in a state of sufficient chemical 

 purity to admit of our calculating a proper formula to represent 

 its composition. But even if we allowed a wide signification to the 

 meaning of the term fibrin, we could hardly regard this substance 

 as fibrin after the chemical reactions which Doderlein observed these 

 flakes to yield ; for he found that they were perfectly insoluble 

 in acetic acid (even when its action was much prolonged) and in 

 sulphuric acid, and that they remained for weeks unchanged even 

 after the blood had become putrid. These properties of the flakes 

 are the very reverse of those of fibrin ; and to include such a 

 substance under the idea of fibrin, would require a greater elasticity 

 of chemical ideas than is even now allowed. Since the relations 

 of pavement epithelium towards acetic and sulphuric acids and 

 towards putrefaction are precisely the same as those of these 

 flakes, according to Doderlein's experiments, we might assent to 

 the opinion formerly advanced by Henle, and regard the flakes as 

 shreds of epithelium from the lining coat of the vessels, if only 

 there was any coincidence between the forms of the two structures. 

 At present Henle is inclined to regard the flakes as adhering 

 membranes of destroyed blood-corpuscles, to which they certainly 

 bear the most resemblance, as is shown by Virchow's experiments, 

 in which he made the membranes adhere by trituration. In 

 the copiously watered blood of the hepatic veins, which is very 

 rich in these cell-membranes, I also found a large number of 



* Mailer's Archiv. 1841, S. 439, and Handworterbuch der Physiologie, 

 Bd. 1, S. 108. 



t Zeitschr. f. rat. Med. Bd. 5, S. 216, and Arch. f. pathol. Anat. Bd. 2, 

 S. 596. 



% Henle's Handb. d. rat. Pathol. Bd. 2, S. 152. 



VOL. II. 



