ON A SOLUTION OF UREA UPON THE BLOOD-CELLS. 289 



blue and red, or of brown and yellow. A similar play ol 

 colour may be witnessed particularly in the spleen, and espe- 

 cially in the amyloid procured from the pulp and from the 

 follicles, whilst nowhere do the blue and bluish-red coloui's at 

 once appear so distinctly as in the Malpighian coils and the 

 afferent arteries of the renal parenchyma. It appears, there- 

 fore, scarcely to admit of a doubt, that sometimes sooner, some- 

 times later, the albuminous siihstance of the tissue disappears 

 and is replaced by the amyloid. 



In those cases, in which the substance differs still more 

 widely from starch, and more close approaches cellulose, the 

 organs affected exhibit the peculiarly pale, transparent, reddish 

 or yellowish, or even brownish aspect, together with the cha- 

 racteristic, as it were, cedematous consistence, which, as I 

 conceive (vol. vi., p. 426), should be described as "waxy," 

 and not as lardaceous. I see with pleasure that the same 

 idea, independently of me, has been adopted in Edinburgh, 

 and the process been at once described as " waxy degeneration" 

 (Monthly Journal, 1854, February and March). In the 

 majority of cases the indurated organs are at the same time 

 enlarged, so that no doubt can be entertained that new matter 

 must have been taken up. 



The coexistence of amyloid disease in the liver, spleen, 

 and kidneys, which has been so often observed, though not 

 so frequently as many believe, of course leads to the suppo- 

 sition of the existence of a common cause — of a constitutional 

 disturbance. A humoral pathologist would naturally suppose 

 a corresponding crasis. But a more cautious ()l)server would 

 be satisfied with saying, as I have done in my former com- 

 munication on the subject of the " waxy spleen," that the 

 common factor is a cachectic condition, whose more special 

 nature remains to be elucidated. 



On the Action of a Concentrated Solution of Urea upon 

 the Blood-Cells. By A. Kolliker. (Zeitsch. f. Wiss. 

 Zool., vol. vii,, p. 183.) 



In the prosecution of a series of researches, respecting the 

 influence of various reagents upon the spermatic filaments, 

 I have almost always employed the blood-cells as a test of 

 the degree of concentration of the fluids experimented with. 

 I was thus led to observe, in the Frog, a remarkable change 

 produced in the blood-cells by a concentrated solution of 

 urea (30 per cent.). The blood-cells gradually acquired an 

 irregular, jagged outline, and were rapidly transformed into the 

 VOL. III. u 



