Imagini ale paginilor
PDF
ePub

There, too, he actually compares the four vessels issuing from the heart for the distribution of the blood to the body, to the four rivers flowing out of Paradise to irrigate the four quarters of the world!1

Casalpinus, to conclude, was unfortunately fettered by Aristotle and Galen, and by the subserviency to authority he had imbibed from the educational system of his country. Casalpinus was not an original and certainly not an independent thinker, or he would have interpreted matters otherwise than he does, and, it may be, have even attained to what I have characterized as the Great Induction.

But this he did no more than any one of his teachers, so that it was reserved for another, son of the freer atmosphere of England, philosopher, scholar, and reasoner like himself, but vastly better anatomist, and indisposed to bow submissively to any authority save that of nature. Referring to the most learned and competent, judicious and impartial critic of his age-Albert Haller, let us say in fine that: "It is not to Casalpinus because of some few words of doubtful meaning, but to Harvey, the able writer, the laborious contriver of so many experiments, the staid propounder of all the arguments available in his day, that the immortal glory of having discovered the circulation

1" Distribuitur sanguis in quatuor venas-scilicet cavam et aortam, arteriam venalem et venam arteriosam,-totum corpus irrigat instar quatuor fluminum ex Paradiso prodeuntium." (Ib., lib. i., cap. 1.)

of the blood is to be assigned."

Nevertheless, on the

30th of October, 1876, in the Hall of the University of Rome, in presence of the Minister of Public Instruction, the Professors and a numerous and distinguished assembly, a marble bust in honour of Cæsalpinus was unveiled to public view, with the following inscription on a tablet underneath:

ANDREE CAESALPINO domo Aretio

Archiatro eximio

Solertissimo Naturæ investigatori
Quod in Generali Sanguinis Circulatione
Agnoscenda ac demonstranda
Caeteros antecesserit

Plantas nondum in Species distributas
Primus ordinandas susceperit

Rerum plurimarum impeditam Intelligentiam
Explicuerit

Universam Morborum doctrinam

Magno cum plausu in hoc Archigymnasio tradiderit
Sodales Medici

et X viri Archigymnasio moderando
Honoris et Memoriæ causa

III pridie calend. Octob. MDCCCLXXVI.

1 66 Adparet non Casalpino, ob paucas aliquas et obscuri sensus voces, sed Harvejo, numerosissimorum experimentorum laborioso auctori, gravique scriptori argumentorum omnium quæ eo ævo proferri poterant immortalem gloriam inventi circuitus sanguinis deberi." (Elementa Physiologiæ, vol. i., lib. iii., Sect. 3, § 32.)

FABRICIUS.

FABRICIUS (Hieronymus). Born at Aquapendente in 1537, Fabricius received his medical education at Padua, and after a term of engagement as anatomical demonstrator, succeeded Faloppius, who had been his master, in the chair of Anatomy, to which at a later period was added that of Surgery, the branch of the healing art in which Fabricius greatly distinguished himself.

Among the works of Fabricius, that on the valves of the veins' is the one which especially interests us. In this he speaks as if he believed he had been the first to observe these Ostiola, and informs us that he discovered them when dissecting in the year 1674, prior to which date he says they had escaped the notice of anatomists. "Who, indeed," he proceeds, would have thought of finding membranes and ostiola within the cavities of the veins of all places else, when their office of carrying blood to the several parts of the body is taken into account?" "The ostiola never

2

1 De Venarum Ostiolis. Petav., 1603. 4to.

2 “Quis enim unquam opinatus fuisset intra venarum cavitatem reperiri posse membranulas et ostiola? cum cum præsertim venarum cavitas quæ ad deferendum sanguinem in corpus universum erat comparata libera, ut liberè sanguis permeare futura esset." (Op. cit. ad initium.)

theless were necessary," as he thinks; "and we may therefore safely say that they were contrived by the Almighty Maker of all things, to prevent over-distension of the veins." They are therefore found in greatest number in the veins of the extremities, because of the violent motions to which they are there exposed; the effect of which is that a great degree of heat is excited in them, and the blood, by reason of the increased heat, is attracted and flows towards the extremities in excessive quantity."

To prevent over-distension, however, was not the most important duty the valves of the veins had to perform; their chief business was, in fact, so to retard the flow of the blood in the vessels as to give the several parts or tissues time and opportunity to appropriate the kind of nutriment they required. Nothing of a valvular nature, on the contrary, was wanted in the arteries. They were not liable to distension, owing to the thickness and strength of their coats; neither did the blood need to be delayed in them, as the flux and reflux in their canals went on perpetually.

1" Procul dubio tuto possumus dicere ad prohibendam venarum distensionem fuisse ostiola a summa Opifice fabricata." (Op. cit.)

2" Procul dubio vi caloris excitatus sanguis ad artus in tanta copia fluxisset atque attractus fluisset." (Ib.)

3" Erat profecto necessaria ostiolorum constructio in artuum venis, ut scilicet sanguis ubique eatenus retardetur, quatenus cuique particulæ alimento fruendi congruum tempus detur. Arteriis autem hæc ostiola non fuere necessaria; neque ad distensionem propter tunica crassitiem ac robur, neque ad sanguinem remorandum; quod sanguinis fluxus refluxusque in arteriis perpetuo fiat.” (Ib.)

The reason why the vena cava and great veins of the neck are generally without valves, is because the brain, heart, lungs, liver, and kidneys require the very freest supply of aliment; and, as being the organs most immediately essential to life, admit of no impediment to its access. If we do find valves at the root of the jugular vein, it is to the end that the blood should be checked when we stoop or lie down, and not be poured like a river in overwhelming quantity upon the brain.'

That the valves retard the blood in the manner described, says our author, is readily shown by an attempt to rub an extremity downwards; "You will then see the course of the blood intercepted and plainly retarded by the ostiola." Among the many illustrative drawings given by Fabricius of the valves in all parts of the body, he has the arm bound as for bleeding, with the turgid veins and the seats of the valves indicated by the slight elevations noticeable here and there; precisely as we find it in Harvey. But the purpose of the two writers was different; Fabricius's object being simply to show that there are valves inthe veins, Harvey's to prove that they made any flow of the blood from trunks to branches impossible.

The most important anatomical fact given to the world between the ages of Servetus and Harvey, which

1"Ea ad sanguinem detinendum ne in declivi capitis situ, in cerebrum instar fluminis irruat atque in eo plus justo cumulatur." (Ib.)

L

« ÎnapoiContinuă »