186 BLOOD. 



altogether unable to isolate them for chemical examination, and 

 secondly, because even if we recognize them as composed of a 

 protein-compound, our knowledge of these substances is still such 

 a vexed question, that it would be impossible to decide whether 

 this nucleus-substance did or did not consist of one of the known 

 and named protein-bodies. 



J. Miiller, and subsequently F. Simon, regarded the nucleus 

 as fibrin in consequence of its solubility in acetic acid and in 

 alkalies, but unfortunately these properties are not characteristic 

 of the substance to which the term fibrin is generally applied; 

 moreover, my observations coincide with those of Jul. Vogel, 

 who found the nucleus very difficult of solution in acetic acid, and 

 hence I cannot regard it as identical with fibrin. Maitland* regards 

 the nucleus as consisting of a peculiar horn-like compound, which 

 he named nucleine ; Nasse very correctly remarks that the substance 

 which Maitland obtained by washing the clot after the removal of 

 the fibrin at the same time contains the cell-walls of the blood- 

 corpuscles, which at all events preponderate very much over the 

 nucleus-substance in question. Hiinefeld regards the nucleus as 

 consisting essentially of fat ; that fat is abundant in the blood-cells 

 will be immediately shown ; but it is scarcely necessary to mention 

 that in the process of exhibiting these nuclei, the fat must always 

 become mixed with them, and consequently must always form the 

 larger part of the object of investigation. 



It has been already mentioned (see vol. i., p. 267), that a con- 

 siderable part of the fat of the blood is accumulated in the blood- 

 cells. Berzelius thought it probable that the so-called phosphorised 

 fat might be chiefly contained in the blood-corpuscles. I have at 

 all events found this view to be so far correct that the fat extracted 

 by ether from the blood-corpuscles of the ox (obtained by means 

 of sulphate of soda, according to Dumas's method) yielded about 

 22% of ash, which had an acid reaction, and consisted essentially 

 of acid phosphate of lime. Since, however, at the present day 

 we are justified in questioning the existence of such a phosphorised 

 fat as was formerly supposed to exist, the idea suggests itself, that 

 what we here meet with is the glycero-phosphoric acid discovered 

 by Gobley in the yolk of egg (see vol. i., p. 243). In the dry 

 blood-corpuscles of the ox I found on an average 2' 249-J of matter 

 extractable by ether. We must, however, not omit to mention 

 that the blood-cells of arterial are poorer in fat than those of 



* An Experimental Essay on the Physiology of the Blood. Edinburgh, 

 1838, p. 27. 



