ADDITIONS AND NOTES TO VOL. II. 525 



another organic substance. No other organic body is formed 

 from the crystalline substance during the preparation of this 

 matter ; only a few phosphates separate from it, as is shown by 

 my comparative analyses of the crystalline substance and of its 

 products of metamorphosis, as well as by my investigation of the 

 acid and saline fluid obtained after the removal of the precipitated 

 bodies by filtration. It is only a metameric modification of the 

 original crystalline substance. 



I regret that Meckel's paper on heematoglobulin, contained in 

 Scherer's Jahresbericht,* has only reached me while these sheets 

 were passing through the press. According to Meckel, oxygen 

 changes hsematoglobulin to a bright red, and carbonic acid to a 

 bluish red colour. It will be seen from my previous remarks, 

 that I did not succeed with certainty in detecting this or any 

 similar change of colour in the pure crystalline substance which I 

 obtained. Moreover, according to Meckel, arterialised hsemato- 

 globulin is not crystallisable, and only the quantity correspond- 

 ing to the globulin of venous blood (dem venosirten Globulin) 

 crystallises from the blood, a fact which it seems to me difficult 

 to prove, as Meckel appears entirely to have overlooked the influ- 

 ence of light upon the formation of the crystals. Although it may 

 be a priori highly probable that heematochlorin and heematoidin 

 appear to be produced from hsematoglobulin by oxidation, I 

 cannot discover any chemical proof of the fact in Scherer's report. 

 Meckel also employed a stream of carbonic acid in the crystallisa- 

 tion of his hsematoglobulin, and in the course of his experiments 

 he made numerous valuable observations, which tend to confirm 

 many otheir researches, more especially those of Kunde and 

 Funke. 



(22) Addition to p. 208, line 6. It appears from the investi- 

 gations of Guillot and Leblanc,t Panum,J Stas, and others, that 

 the substance which they regard as casein, is contained in a larger 

 quantity in the blood of pregnant and puerperal women than in 

 ordinary blood. The supposed occurrence of casein in the blood 

 has been already noticed in page 483 of this volume. 



Notwithstanding the proofs which Panum and Moleschott 

 have brought forward to demonstrate the existence of casein in 

 the blood, Scherer is still by no means convinced that their casein 



* Jahresber. d. ges. Med. 1852,S. 95. 

 t Compt. rend. T. 31, p. 585. 

 t Arch. f. path. Anat. Bd. 3, S. 268. 

 Compt. reud. T. 31, p. 029. 



