ADDITIONS AND NOTES TO VOL. I. 495 



the open air, as has been observed in numerous instances (we need 

 here only refer to the experiments of Scherer and Panum) ; but 

 all persons who are conversant with such investigations must be 

 aware of the extreme difficulty of tracing these metamorphoses, 

 owing to the high atomic weight of these bodies. In the mean- 

 while,, I am disposed to regard this crystalline substance as a com- 

 bination with carbonic acid ; and this view seems to derive 

 confirmation, not only from its formation in a current of carbonic 

 acid, and its spontaneous production in diseased liver and from 

 putrefaction, but also from the incapacity of the solution to re- 

 crystallise after the dried or dissolved crystals have been placed 

 under the air-pump ; and finally, from that decided development of 

 carbonic acid which we perceive in the moist crystals in vacuo, 

 and the obviously more abundant development of gas in vacuo 

 when acetic acid has been previously added to the solution. The 

 globulin of the crystalline lens behaves in precisely the same 

 manner, excepting that it is not crystallisable, and does not 

 require the previous application of oxygen for its separation by 

 carbonic acid. . When a stream of carbonic acid is passed through 

 the solution of globulin, the latter is precipitated, but this pre- 

 cipitate, on being shaken in pure water and in the open air, again 

 dissolves into a clear fluid, from which the globulin may be again 

 precipitated by carbonic acid. The crystalline substance which 

 has been treated with salt and acetic acid (corresponding to 

 Panum's acid albumen) appears simply to undergo a rnetameric 

 metamorphosis : it does not separate into several different 

 substances on being coagulated by boiling (as Panurn maintained 

 was the case with albumen in the formation of acid albumen), 

 but is rendered far more susceptible towards atmospheric influences 

 than the original crystalline substance. 



(45) Addition to p. 396, line 10 from bottom. Scherer* has, 

 however, recently found a substance in Jeucaemic blood which 

 appears, from all its reactions, to be nothing else than glutin, and 

 which consequently stands, in a chemical point of view, between 

 the protein-bodies and gelatigenous matters. 



It is, moreover, worthy of notice, that the embryo, up to the 

 final period of its leaving the egg, contains no gelatigenous tissue 

 (Hoppef). Animal cell-walls and nuclei appear never to consist 

 of gelatigenous tissue (Hoppe). 



* Verhandl. d. phys.-med. Ges. zu Wurzburg." Bd. 2, S. 321-325. 

 t Arch. f. pathol. Anat. Bd. 5, S. 174. 



