SPLEEN. 



Haller fays Jilfo that it contains more water, the proportion 

 of this element in it, compared to that in other blood, being 

 as 4i to ^ J. The thick part fubfiding to the bDttom of the 

 veflel was lefs ; as 3 to 6. Sir Everard Home confirms the 

 fad of the greater quantity of ferum in fplenic blood. 

 (Phil. Tranf. 1808, p- 138.) Neither, according to the 

 reprefentation of Haller, are thefe the only diltinguifhmg 

 charafters of fplenic blood. It has been found, he fays, to 

 contain more volatile fait, *id lefs empyreumatic oil. The 

 experiments on which the above obfervations are grounded 

 afforded fimilar refults on repeated trials, and in various 



animals. 



The fpleen is very fmall in the foetus, and appears re- 

 markably fo, if compared to the kidnies or liver. It ra- 

 ther increafes towards the end of pregnancy. No remark- 

 able changes occur in it after birth : in old perfons it is often 

 diminiflied ; and its external coat is thicker. 



A fpleen, or at leaft a body fo confidered, and called by 

 that name, exifts in all the orders of the vertebral divifion 

 of animals ; but, if we may judge from the iize, its im- 

 portance feems to diminifh fucceffively from mammalia to 

 birds, thence to reptiles, and from them to fifhes. Mammalia 

 refemble man in having the fpleen placed clofe to the left end 

 of the ftomach ; but they exhibit confiderable varieties in the 

 fize, figure, colour, and texture of the organ. It is pro- 

 portionally large in man, being twice as large as in the ox 

 for example. In birds, reptiles, and fifhes, the fpleen is 

 not only (mailer, but firmer and more rounded j not fo con- 

 ftantly placed near the ttomach, but in the midil of the me- 

 fentery for example. The relations and fources of its blood- 

 veflels are alfo different. Inftead of a large peculiar branch, 

 it has fmall branches from a ilomachic artery, or from the 

 mefenteric. 



The ufe of the fpleen ftill remains a problem, towards the 

 elucidation of which the inveftigations of fo many anatomifts 

 and phyfiologifts have hitherto afforded very imperfect data. 

 In beginning his obfervations on this fubjeft, Haller very 

 fenfibly admonifhes his reader that " he is plunging into the 

 region of mere conjefture, darker than in the cafe of any 

 other vifcus." We might have hoped to derive fome light 

 from the difeafes under which it frequently fuffers, and from 

 the experiments, in which it has been removed in animals. 

 The inferences, however, to which we arrive in this way, 

 are only of the negative kind ; they enable us to deltroy or 

 refute, but not to baild up or eitablifh. The fpleen may 

 be found confiderably altered in texture, where the indi- 

 vidual has enjoyed good health before death, or has died of 

 ether complaints. It is often enormoufly enlarged, without 

 materially affeAing the health ; and, on the other hand, where 

 ill effefts are produced, they have no peculiar charafter, 

 affording illuftration of the ufe of the organ. 



The experiment of removing the fpleen feems to have 

 been performed in very ancient times. Pliny fay?, that 

 animals will live after this part has been torn out (lib. xi. 

 c. 30.) ; and the fame fatt is noticed in the Talmud (Ginz- 

 burger. Medic. Talmud, p. 11.) Haller cites various in- 

 ftances, in which the fpleen has been loft in the human fub- 

 ject ; particularly Leon. Fioravanti, teforo della vita umana, 

 1. li. c. 8. Phil. Tranf. N°45i. The removal of it from 

 the dog is an experiment repeated over and over again. 

 (See Haller, t. vi. p. 421.) We find that animals, and 

 even human fubjcfts, have lived without a fpleen, and en- 

 joyed tolerable health. Sometimes the experiment has been 

 fatal, but not from the lofs or interruption of any func- 

 tion, that could be afcribed to the fpleen. We find that 

 dogs have been lively, fat, and even plethoric; that they 

 have had good appetites ; that bitches have produced 



young. Some thonght they wire more falacious ; others, 

 that they made water more frequently. In fome cafes 

 appearances were noticed, that might be referred to im- 

 perfeAion in the digeftive procefs, as borborygmi. .The 

 liver is faid to have fuffered, in a few inftances : in moll, 

 however, there feems to have been good bile made ; and 

 generally no particular ill effeft was experienced. 



The inference, then, to be collefted from thefe fources 

 is, that the funftion of the fpleen is of fo httle importance, 

 that the alteration of its texture by difeafe is not marked 

 by any unequivocal fymptom, and even that its entire re- 

 moval is hardly followed by any fenfible effeft. 



It has been a generally received, and long prevalent 

 notion, that the office of the fpleen is related to that of the 

 liver ; that the blood, either by its retarded motion througli 

 the ferpentine fplenic veilels, its ft agnation in the fplenic 

 cells, or other changes wrought in it by the aftions of the 

 fpleen, acquires peculiar properties, rendering it fit for the 

 fecretion of bile in the liver. It is fuppofcd that the fplenic 

 blood is loaded with carbon, which the aft ion of the liver 

 feparates from it. We do not ufually meet with fuch ar- 

 rangements as thefe in the animal economy : indeed no in- 

 ftance could be adduced of the like nature ; — one organ to 

 carbonize the blood, that it may be decarbonized by 

 another ; or a part to produce changes in the blood, fitting 

 it for the fecretion which is to be performed by another. 

 The tiffue of each gland has the power of extracting its pe- 

 culiar fecretion from the common mafs. That the fpleen 

 produces changes in the properties of the blood is not yet 

 clearly proved : ftill lefs is it proved that fuch changes, if 

 produced, are in any way concerned with the biliary fecre- 

 tion. Further, bile is fecreted where the fpleen has been 

 removed ; and it was fecreted, in the cafe recorded by Mr. 

 Abernethy, where the vena portarum emptied its blood into 

 the inferior vena cava. W^e obferve no conltant relation 

 between the fpleen and liver ; the former is extremely fmall 

 in many birds, reptiles, and fifties, where the liver is large. 



The clofe neighbourhood of this organ to the ttomach, 

 and the connexion of their blood-veffels, have led to the 

 conjefture that they are connefted in funftion. It has been 

 imagined, that when the ftomach is emptj, the fpleen, like 

 a fponge, fwells with blood, and affords a refervoir for the 

 quantity of that fluid, which the blood-veffels of the ftomach 

 do not require in the inaftive ftate of the organ ; while, on 

 the contrary, when this bag is dillended with food, and the 

 procefs of digeftion demands a more copious afHux of fluids 

 into the ftomachic veflels, the preffure of its great extremity 

 empties the fplenic fponge, and thus caufes a greater flow 

 in the other parts of the cojliac fyftem. This, again, is all 

 imaginary : not a fingle point of it founded in obfervation. 

 It is quite inapplicable to the three lower claffes of vertebral 

 animals, where the pofition of the fpleen in many inftances, 

 and its firmnefs in feveral, are quite incompatible with the 

 explanation. 



In two papers, publiftied in the Philofophical Tranfac- 

 tions for 1808, on the ftrufture and ufe of the fpleen, fir 

 Everard Home attempted to prove, that fluids are conveyed 

 from the cardiac end of the ftomach into the fpleen, and 

 thus arrive in the general circulation, without the interven- 

 tion of the general abforbing fyitem and thoracic daft. 

 Having tied the pylorus, he injefted coloured fluids into the 

 ftomach : they were partly abforbed, and manifeftcd their 

 prefence in the circulating fyilem by changes produced iu 

 the urine. When rhubarb was ufed, the cut furfacc of the 

 fpleen produced a decided yellow tint on paper, and the 

 ferum of the fplenic blood manifefted the prefence of rhu- 

 barb, on the addition of potafti ; when no fuch phenomena, 



were 



