438 OF NUTRITION. 



subject, in blood drawn by the prick of a needle from an inflamed pimple, the 

 base of a boil, the skin in scarlatina, &c. And the Author, without any know- 

 ledge of these observations, had remarked a very obvious difference between 

 the proportions of white corpuscles, in blood drawn from a wound in the skin 

 of a frog immediately upon the incision being made, and in that drawn a few 

 minutes after ; and had been led, like the observers just quoted, to refer this 

 difference to a determination of white corpuscles to a part irritated. The ab- 

 solute increase, sometimes to a very considerable amount, in the quantity of 

 white corpuscles in the blood of an inflamed subject, has been verified by Mr. 

 Gulliver and several other observers. These facts, therefore, afford strong 

 ground for the belief, that the production of fibrin in the blood is closely con- 

 nected with the development of the white corpuscles ; and when we consider 

 them in connection with the facts previously urged, there scarcely appears to 

 be a reasonable doubt, that the elaboration of fibrin is a consequence of this 

 form of cell-life, and is, in fact, its express object. This view derives further 

 confirmation from the following recent experiment of Mr. Addison's.* "Pro- 

 vide six or eight slips of glass, such as are usually employed for mounting 

 microscopical objects : and as many smaller pieces. Having drawn blood from 

 a person with rheumatic fever, or any other inflammatory disease, place a drop 

 of the colourless liquor sanguinis, before it fibrillates, on each of the large slips 

 of glass ; cover one immediately with one of the smaller slips, and the others 

 one after another at intervals of thirty or forty seconds : then, on examining 

 them by the microscope, the first will exhibit colourless blood corpuscles in 

 various conditions, and numerous white molecules distributed through a more 

 or less copious fibrous net-work ; and the last will be a tough, coherent, and 

 very elastic membrane, which cannot be broken to pieces nor resolved into 

 smaller fragments, however roughly or strongly the two pieces of glass be made 

 to rub against each other. This is a * glaring instance' of a compact, tough, 

 elastic, colourless, and fibrous tissue, forming from the colourless elements of 

 the blood; and the several stages of its formation may be actually seen and 

 determined. Numerous corpuscles may be observed, in all these preparations, 

 to have resolved themselves, or to have fallen down into a number of minute 

 molecules, which are spread out over a somewhat larger area than that occu- 

 pied by the entire corpuscles ; and although still retaining a more or less per- 

 fectly circular outline, yet refracting the light at their edges, in a manner very 

 different from that in which the corpuscles themselves are seen to do. It is 

 from these and various other larger and more irregular masses of molecules or 



* Transactions of the Provincial Medical Association, 1843. 



j- A different view of the cause of the production of fibrin, however, has been enter- 

 tained by some eminent physiologists; and it does not seem right to allow the opinions of 

 Wagner, Henle, and Wharton Jones, to pass without notice, even though they appear to 

 the Author to be easily set aside. By these observers, the elaboration of fibrin has been 

 attributed to the red corpuscles, and' has been regarded as one, at least, of their special 

 functions. Nearly all the arguments, however, which have led us to assign this duty to 

 the white corpuscles, tell equally against the doctrine now under consideration. The pre- 

 sence of fibrin in the circulating fluid may be regarded as a universal fact; but the red 

 corpuscles are restricted to vertebrated animals: how, then, is the plastic element elabo- 

 rated in the invertebrata! The number of the red corpuscles in the blood of different 

 classes bears an obvious relation to their amount of respiratory power, and to the func- 

 tional activity of the several organs, which is closely connected with the amount of oxygen 

 introduced into the system; but it does not bear the same relation with the activity of the 

 formative processes, which may be taking place energetically, (as in the development of 

 the embryo, or in the reparation of parts in the adult), in a state of functional quiescence. 

 The pathological evidence that the red corpuscles are not the elaborators of the fibrin, 

 appears to the Author to be quite conclusive. Whilst the quantity of fibrin is so remark- 

 ably increased in inflammation, the number of red corpuscles' undergoes no decided 



