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tured, has that direct nutrient relation with the structure which 

 has just been assigned to the secerned fluids. But the fact proves 

 only that blood-vessels ramify very minutely in the osseous tex- 

 tures, and that blood escapes in consequence of the abrasion of 

 their coats. I would repeat also, in reply, that the relation of 

 the nutrient fluid is with particles composing the minutest 

 cylinders, to which blood cannot pass by vessels, unless it can be 

 shewn that parts less than possible cylinders may be permeated by 

 cylinders. 



14. In agreement with the same views, we find that in the 

 processes of organization, subjected to our inspection, as in the 

 regeneration of parts destroyed by ulceration, or in the union of 

 wounds, the nidus of growth is not blood, but a secretion; that which 

 is called coagulable lymph. Whether this is the common product 

 of secerning extremities for purposes of nutrition, or growth, we 

 can perhaps scarcely affirm ; it appears, however, to be exhibited as 

 such under disease, and to accomplish this end as a product of 

 dissimilar structures. Thus I have witnessed the production of a 

 circumscribed fungus, which has been cut off" and grown rapidly 

 again, and this growth was preceded visibly by a copious deposi- 

 tion of lymph. That a similar lymph is a precursor to organiza- 

 tion in other instances is well known. 



15. Upon the collective strength then of these circumstances 

 we may venture to assume that the nutrient fluid is a product of 

 secerning extremities of arteries; that it is perhaps generally this 

 lymph of which we have just spoken, which, containing infinite 

 properties (as all other things do), is formed into the various struc- 

 tures by finding new relations in the spiritual properties of each. 



16. If it be granted that the nutrient fluid of the body is such 

 a product of arterial blood, the changes which this blood sustains 

 in consequence of the exertion of a process by which the fluid is 

 produced, may be next considered. It is the business of analysis, 

 or of analysis and synthesis conjointly, to specify what is the con- 

 stitution of the separated material, and to demonstrate the precise 

 change which arterial blood has suffered. In other words, sup- 

 pose the fluid separated to be coagulable lymph; this identity of 

 it will be ascertained satisfactorily only by separating coagulated 

 lymph from arterial blood, and observing if the same changes oc- 

 cur as in the separation accomplished by a secerning process; and 

 again, by adding coagulable lymph to the blood, which has 

 suffered secretion, and observing whether its former identity is 

 restored. But these minute acts of the analytical inquiry are much 

 more easily directed than performed. We 'must now, as formerly, 

 be content to consider grosser circumstances. 



17. We observe at about this stage of the circulation, viz. 

 when arterial blood has reached the capillary system, that a great 

 and distinctive change occurs in its appearance and properties: 

 this change is implied in the conversion of arterial into venous 

 blood. The question first to be decided is, where this conversion 



