258 [Recess, 



VII. "On Stasis of the Blood, and Exudation." By RICHARD 

 NORRIS, Esq. Communicated by Dr. SHARPEY, Sec. U.S. 

 Received August 28, 1862. 



Confusion has been introduced into the question of stasis, as related 

 to inflammation, by neglecting to discriminate between the various 

 forms of stasis, of which there are four. 



1 . If the frog's web be exposed to certain irritants (e. g. chloro- 

 form), the arteries are so constricted that the heart-force is tem- 

 porarily shut off from the capillaries, which become packed by the 

 reflux of blood from the veins. This form of stasis is dissipated 

 immediately on the cessation of the arterial constriction. The blue- 

 ness of the extremities consequent upon exposure to cold is probably 

 dependent on the same mechanism. 



2. The second form of stasis depends upon such enfeeblement of 

 the heart's force as interferes with the due propulsion of blood into 

 the extreme vessels. It also disappears upon the re-establishment 

 of a sufficient propulsive power. 



3. The third form is that described by H. Weber as follows : 

 " If a limb [of a frog] be strangulated, there arises in its web within 

 four to eight hours, without any irritation being applied, a stasis 

 which is identical with inflammatory stasis, except that after sixty 

 hours' duration it will be dissipated as soon as the circulation is set 

 free." The removal of this stasis by the re-establishment of the 

 circulation distinguishes it from inflammatory stasis, and shows its 

 relation to the forms already described. 



4. The fourth form of stasis is producible (artificially) by the 

 application of irritants, and has for its specific characteristics 



a. It is readily induced when the heart-force is unimpaired 

 and the blood-channels are free. 



/3. It requires hours or even days for its dissipation, or it may 

 even be irresolvable. 



y. It presents under the microscope a homogeneous appear- 

 ance, as if the vessels had been injected with a tinted size or 

 gelatine. The outlines of the corpuscles are undistinguishable. 

 I call this "homogeneous" or "inflammatory" stasis. 



It is unnecessary to offer additional evidence upon the first 



