306 COLOURING MATTERS. 



water, alcohol, and ether, abstracts from them all soluble salts, 

 and the fat, which in itself amounts, according to my investigations, 

 to at least 2%. 



The ratio of the hsematin to the blood varies in diseases for the 

 most part with the number of the blood-corpuscles ; but whether 

 the ratio of the hsematin to the globulin of the blood-corpuscles 

 be constant, or whether the hsematin be liable to greater variations 

 than the globulin, are questions which in the present state of organic 

 analysis it is impossible to answer. 



Origin. There is nothing in the chemical constitution of 

 hsematin which throws any light on the mode of its formation ; 

 we do not know whether it is directly formed from the constituents 

 of the food or from the products of metamorphosis of effete tissue ; 

 and we have no certain knowledge regarding the part of the organism 

 in which it is produced. The chyle certainly contains iron, and 

 hsematin exists in the thoracic duct ; but iron is not hsematin, and 

 the small quantity of the last-named substance may have passed 

 from the blood through the mesenteric glands into the chyle, or may 

 have arisen from the blood-corpuscles which have passed with the 

 splenic lymph into the chyle. If the formation of hsematin took 

 place in the chyle it would not be after prolonged fasting that we 

 should find it richest in this substance. Chemistry, as we have 

 already observed, affords us no assistance in reference to the for- 

 mation of this body; we must, therefore, at present, confine our 

 attention to physiological facts, in order that we may obtain a safe 

 starting-point for further chemical enquiries. 



Most physiologists of the present day coincide in the opinion 

 that the red blood-corpuscles are developed from the colourless 

 ones ; but whether they regard the former as nuclei of the latter, or 

 as independent cells produced from them whether they adopt the 

 views of H, M tiller,* of Gerlach,f or of Kollikei J they must in any 

 case admit that the red pigment of the blood is primarily formed 

 within the enveloping membrane of the cell. Further, physiological 

 enquiry demonstrates, almost beyond a doubt, that the blood pig- 

 ment is first formed in the perfected cells, and, moreover, affords 

 us some indication, however indistinct, of the source from whence 

 this pigment may possibly have been produced. Nasse, Hiinefeld, 

 and others, have proved that the granular matter visible in many 

 of the coloured blood-corpuscles is merely fat ; indeed in the yolk- 



* Zeitschr. f. rat. Med. Bd. 3, S. 204-278. 

 t Ibid. Bd. 7, S. 70-90. 

 J Ibii. Bd. 4, S. 112-1CO. 



