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no inconvenience in some instances from its loss. This fact 

 proves that the use of the spleen, if it has any, is but of trivial 

 importance; accordingly, a function of the hydraulic kind only 

 has been supposed to belong to it. It has been considered, in- 

 geniously, as a mere reservoir of blood, subservient to the function 

 of the stomach. The theory alluded to is this : when the stomach 

 is distended by food, it compresses the soft texture of the spleen, 

 diminishing the quantity of blood which would otherwise pas* to 

 the splenic arterial ramifications, and thereby determining a 

 greater quantity to the stomach, through the vasa brevia and 

 gastro-epiploica sinistra, branches given oft* ^o the stomach, 

 HI the course of the spleuic artery to the spleen. The theory 

 further assumes, that the stomach receives an augmented supply 

 of blood, at the times when it is most required, for the purposes 

 of digestion. 



4. That such an effect may take place from this arrangement, 

 in some degree cannot be denied; at the same time it may be 

 suggested that the pressure which the stomach may, under any 

 circumstances, be supposed to exert, is scarcely sufficient to 

 diminish the area of an artery of the smallest size, when blood is 

 forcibly impelled through it with the usual velocity of the circula- 

 tion. It may be suggested, that the momentum of the blood, cir- 

 culating in the spleen, presents a considerable resistance to any 

 cause of compression, and that the resistance is likely to be the 

 more effectual, when the compressing substance is from its texture 

 and configuration (that of a membranous cavity partially occupied 

 byjhtid contents) even more easily compressible than the spleen 

 itself. Some truth however may be allowed to this theory; and 

 the trifling degree in which the spleen, according to it, can be 

 conducive towards any useful purpose, agrees very well with the 

 slight derangement which has been observed to follow its entire 

 removal. It may be observed further, in the way of objection to this 

 theory, that determination of blood to particular seats takes place 

 either regularly, or at intervals in many, perhaps in most, diseases ; 

 and that such determination is produced without any such arrange- 

 ment as that which is here supposed to be merely subservient to 

 it. But, without drawing our examples from the phenomena of 

 disease, we may quote one instance in which the occasional in- 

 crease of the quantity of blood, circulating in an organ, takes 

 place indispensably for the purpose of an occasional function. In 

 this instance (furnished by the phenomena of the pudic artery) 

 nature is seen to accomplish the increased determination of blood 

 to a part with no other mechanism or contrivance than that which 

 belongs to its own vessels, which are made liable to a general, and 

 an occasional state of dilatation. It must be observed iu regard 

 to the spleen, that the fact just quoted furnishes an analogy 

 against the theory proposed respecting it; and further, that we 

 perhaps ought scarcely to conjecture that complicated means are 

 at one time instituted by nature, for a purpose which is in other 

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