In consequence of what has been said — which I might also corroborate by many other facts could I go more into detail— it is im possible to imagine the development of a special lymph in the spleen ; and hence the theory which ascribes to the spleen a relation to the lymphatic system, and considers it as in a certain manner a large lymphatic-gland, is utterly devoid of meaning. In this manner there remains as a last resource the view, that changes occur in the blood itself con tained in the spleen. But what is the na ture of these changes ? Are blood corpuscles possibly formed in the spleen, as has been already so often supposed ? Certainly not; for in the most rigorous examination of the blood in the spleen and the larger splenic vessels, jugt as in the spleen-lymph, no trace whatever of the formation of blood globules can be detected, much less in blood which is exactly reversed, and is exhibiting, as I might say, at every step the plainest and most lively indications of a dissolution and decomposition. Let us recall to mind the details already given of the .condition of the blood globules in the spleen. Upon the facts there men tioned, in the year 1847* I founded the con jecture that the blood corpuscles undergo solution in the spleen, and that their colouring matter is employed in preparing the colouring matter of the bde ; a conjecture which seems to me preferable to all those which have hitherto been offered concerning the function of the spleen. If the fact be made out that new blood globules are continually arising from the cells of the chyle, it is just as certain that the blood globules must also slowly dis appear in order to make room for those newly arising. And if it be considered that nobody has yet seen the least trace of a solution of blood globules in any other organ, and that, on the contrary, I have found in the spleen a healthy organ, in which, in all four classes of vertebrate animals, blood corpuscles are almost constantly undergoing decomposition, even in uncommon quantities, it will, I think, be conceded to me that I have some grounds for setting forth the hypothesis here given. It is, indeed, as yet not altogether settled whether the changes of the blood seen by rne are normal or abnormal ; but, as was previously remarked, so long as their patho logical nature is not proved with certainty, I must continue to regard them as physiological and pertaining to healthy life. But this is not saying that they occur in all creatures in the method described above. It is highly possible that blood globules undergo disso lution in the spleen without previously form ing the cells containing blood corpuscles : an opinion which is corroborated by the blood globules described above as occurring in the blood of the splenic vein of the dog and fresh-water perch : these contained crystals of hgematine or some kindred substance, and were evidently near their destruction. In deed, it is even possible that such a direct mode of dissolution may be the rule in some animals, perhaps even in many. And although I have regarded the spleen as an organ in which the blood corpuscles undergo disso lution, yet I have not maintained therewith that it is in all animals the only organ in which any thing of this kind occurs: it would therefore in no way militate against my theory if it should ever turn out that in the kidneys of fishes, the vessels of which are arranged so peculiarly, a constant and physio logical solution of blood globules obtained. The following circumstances also speak for my hypothesis. That in no other way can any reasonable account be given of the changes of the blood in the spleen. Further more, that it elucidates the relation of the spleen to the portal system of veins; since ac cording to it, the dissolved blood corpuscles are subservient to the formation of the bile, the colouring matter of which is so nearly allied to that of the blood. Finally, that, as will be more fully stated below, the patho logical facts are proportionally in unison with it.
On all these grounds I am therefore in clined to defend the hypothesis first set forth by me of a destruction of the blood globules in the spleen ; and the more so, that J. Be clard has lately maintained, that the blood of the splenic vein is always poorer in blood cor puscles than that of the other veins. Ile has stated this in a memoir which was laid be fore the Academie des Sciences in Paris on the 17th January, 1848, and published in the " Archives generates de Medicine" of Oc tober to December, 1848. Since J. Beclard's results are an important support to my hypo thesis, I have permitted myself to communi cate here the most important of them. Be dard has analysed the blood from the lower branch of the splenic vein, and that from the jugular vein, in fourteen dogs and two horses. In most of the instances of the analysis, (I.) the water, (2.) the blood corpuscles and fibrine, and (3.) the albumen and salts, were separated from each other ; and only in the horses were the blood corpuscles and fibrine obtained separately. A deficiency of the blood globules and fibrine was always present in the splenic vein, which diminution out of a 1000 parts of blood, amounted to the fol lowing quantities in the sixteen cases.
16.54 15.94 8.5137-11 19-67 13.06 19.43 20.80 14.91 12.82 10.88 9.40 o 13.92 16.0613.60 14.78 On an average of the sixteen cases, the de ficiency amounted to 16.08 parts. As regards the albumen, on the contrary, there was a constant increase of this constituent in all the sixteen cases, in an average of 13-02 parts. Finally, in the two analyses in which the quantity of fibrine was certified, there was the extraordinary increase in its quantity in the blood of the splenic vein of 0.3 and 0.5 parts. Beclard deduces the same conclusion from these facts which I have drawn from my micro scopical examinations ; namely, that the hlood corpuscles normally undergo dissolution in the spleen ; and I regard this conclusion as neither more nor less correctly deduced than mine, for it is clear that the results of his ana lyses may solely depend upon this fact, that in the animals he examined, the changes which I have verified in the blood globules of the spleen, were going on in an energetic manner. If these visible changes of the blood globules, — which certainly occur in a most exquisite manner in the horse and dog,—if they be nor mal appearances, then is the diminution in the quantity of the blood globules, which Be clard found on analysis, also a normal phe nomenon ; but if not, then he only examined a blood partially deprived of its globules by stagnation and effusion. The results of che
mical analysis would then only be secure, if it were at the same time shown, that there were no visible changes of the blood globules in the spleens of the animals examined. Until this takes place, Beclard's conclusion will remain, like mine, hypothetical ; although this is in no way diminishing the merit of his ob servations, since I hold my own hypothesis as one which I am perfectly justified in pro pounding in the present state of our know ledge. But even if we suppose that the blood corpuscles are destroyed in the spleen, it is nevertheless a question how this dissolution is super-induced, and at what time it comes to pass. As regards the first of these points, in my writing previously mentioned I ex pressed the opinion, that the spleen is a con tractile organ, and may, by virtue of its con tractility, be able to dilate and contract itself, — to fill itself with blood, and again to expel the blood from it. In the state of filling itself with blood, a stagnation of blood occurs in the smaller vessels, perhaps even an extravasa tion ; and in this stagnant blood, the blood globules undergo destruction, since they slowly dissolve themselves, either free or in closed in cells. This view I still regard as cor rect. For, firstly, it is a matter of fact that the spleen does enlarge and diminish its size, and certainly under vital circumstances which are altogether normal. Very many of the older observers have accepted this fact . as Lieu tand, Haller, Stuckeley, Rush, Cla;ke, Hodg kin, Home, and Dobson. This is shown by an examination of the splenic region in the living human subject (Piorry). So also it is shown by vivisection . of animals, in whom I have myself seen (and especially in the dog) a very distict diminution and rounding of its outer surface. Finally, Landis*, by weighing the spleen, has recognised a distinct increase and diminution of weight. He examined at different times thirty rabbits, and finds that the average weight of the organ in five obser vations was : 12 hours after eating, 0'768 grammes.t 5 -588 „ 8 ), -548 „ 24 -526 „ 48 71 '510 „ 2 .441 „ Now although it may be freely conceded that an organ like the spleen is subject to so many variations in respect of size as to render thirty observations much too small a number to afford any very definite information con cerning its increase or decrease of size, it must, nevertheless, be considered, that Landis has examined the proportion of the spleen to the whole body, and to many other organs, as the stomach, liver, and kidneys, and that from this means he derived a confirmation of what the estimate of its absolute weight had previously taught ; so that his observations must be regarded as a meritorious contri bution to our knowledge respecting the changes of volume which the spleen expe riences. We now ask, secondly, how these changes come to pass ? Beclard states that the spleen enlarges and becomes filled with blood in consequence of the splenic vein being com pressed by a muscular force ; but the nature of this he has not stated, nor can I regard his view as correct. I believe myself to have propounded a better theory when I stated, that the spleen becomes turgescent in conse quence of the relaxation of the muscular fibres which exist in its balks, coats, and vessel-sheaths ; or in animals from whom these are absent, through a relaxation of the muscular fibres of the vessels themselves. A constriction of the splenic vein cannot be supposed to obtain, since the muscular fibres which it contains are but very little de veloped, and no other compressing force is present ; while, on the contrary, we know that in all animals the splenic artery is uncom monly muscular, and that the partitions of the spleen themselves contain distinct muscular fibres. It is these muscles and no others which, according to my researches, produce the distension of the spleen ; but not through their contracting together, but by their re laxation, which brings with it a disterrsion of the vessels with blood, and a slower circu lation of this fluid. The diminution in the size of the spleen occurs simply through the contraction of the muscular parts just named. Precisely in the same manner the corpora cavernosa of the penis become filled with blood by a relaxation of the muscles situated in their fibrous partitions ; and become poorer in blood, and smaller in size, when the mus cles again contract themselves. Of course, both here and in the spleen, the nerves play an important part in the process ; probably in consequence of antagonistic relations be tween them and other parts of the nervous system, which at present cannot be accu rately indicated. Thirdly, and finally, it may be asked, whether the blood corpuscles simply dissolve because the blood of the spleen be comes stagnant at certain times, or whether special influences are necessary to this effect ? whether the parenchyma of the spleen or the Malpighian corpuscles may not secrete a juice, a " succus lienalis," of which the earlier authors speak, which exerts a solvent in fluence on the blood corpuscles ? As a kind of vague answer to this question, I have ex amined the parenchyma with respect to its reaction, and have found that without ex ception it has an energetic acid reaction. This appeared to me very extraordinary, and the more so when I thought of the great quan tity of blood which the organ contains; and I was already captivated by the conjecture that this acid reaction might be of great import ance. But I found that litmus paper was just as much reddened by the liver and kidneys of the calf and rabbit ; and, further, that the tnuscular substance of the heart and the muscles of the trunk have the same effect. So that this acid reaction appears to be a general phenomenon, which is probably due to the fact, that the acids lately found by Liebig in muscle (lactic and inosic acids) also occur elsewhere. At any rate since there is as yet no exact chemical analysis of the spleen, I cannot express myself con cerning the import of this vigorously acid re action of its parenchyma ; although it is very conceivable, that the acid reaction does not depend on the same causes in all organs.