BLOOD. l',7 



globular, or else into flocculent mucous masses. Fibrin is 

 therefore obviously formed in the active metamorphosis of the 

 blood ; and that portion which preexists in the chyle is modi- 

 fied and rendered more plastic. It is a well-known fact that the 

 respiratory process not only increases the plasticity of fibrin in 

 the bloodj but also its quantity, and that on the other hand the 

 amount of fibrin diminishes in blood which is not efficiently 

 brought in contact with oxygen. As the blood-corpuscles 

 principally consume oxygen during their change, it appears 

 very probable that the fibrin is produced during this process. 



This Adew is elucidated, and I may say confirmed, by my 

 analyses of the blood, in which it appears that with very few 

 exceptions, the amount of fibrin always varies inversely with 

 the mass of the blood-corpuscles, or, in other words, that the 

 more corpuscles there are, the less in quantity is the fibrin, 

 and vice versa. This fact is readily explained by the adoption 

 of the view that fibrin is formed from the blood-corpuscles ; for 

 it is obvious that the quantity of fibrin in the plasma must in- 

 crease during an extraordinary consumption of the corpuscles. 



Let us now inquire which of the constituents of the blood- 

 corpuscles has been employed in the production of that most 

 essential ingredient of the plasma, the fibrin? It can hardly 

 be the globulin, for that forms from 4 to 105 of the blood, and, 

 being a protein-compound, is so intimately connected in its 

 chemical relations to fibrin, that if we were to suppose that it 

 were converted into fibrin, we should expect to meet >vith a 

 much greater quantity of this latter constituent in the blood 

 than we find actually existing ; still less can it be the hsematin ; 

 indeed, the use of this appears to be to facilitate and to maintain 

 the independent metamorphosis of the blood-corpuscles, through 

 its energetic capacity for the absorption of oxygen, and through 

 its own metamorphosis, instead of forming a product for the 

 further nutrition of the plasma. The capsules and the nuclei 

 still remain for consideration. Of the former avc know very 

 little, but the latter actually possess chemical characters which 

 approximate them to fibrin, so that there is no impediment to 

 the supposition that this important constituent of the blood is 

 formed from the nuclei by a metamorphic process, accompanied 

 probably by the absorption of oxygen and the separation of 

 carbon. 



