As opportunities of dissection became more numerous, the de fects of the old wri ters in anatomy were discovered. Ingeni ous men, hating gone through their edu cation, determined to consult nature for themselves. It is not to be wondered at that errors and deficiencies in anatomy were found in every page of the works of Galen, to say nothing, of I lippoc rat es, since the human body, in his time, could not be consulted for information. The authority of the Greek writers on these subjects was quickly demolished, and anatomy began to be taught from the subject itself. We must not omit the influence, which the writings of our immortal countryman, Ba. con, had on the prosecution of natural knowledge, and in every species of rea soning. The philosophy of Aristotle was driven from tlic pre-cminent station which. it had so long occupied, to make room for the only solid and secure methodof obser vation, experiment, and induction. At this time the Academy del Cimento arose in Italy, the Royal Society in London, andthe Royal Academy in Paris. Front this peri od, the important doctrine of rejecting all hypothesis, or general knowledge, till a sufficient number of facts shall have been ascertained, by careful observation and dicious experiments, has been every day growing into more credit. The anatomists and phisiologists of these times distin guished themselves by a patient observa tion of nature itself, and an accurate ac count of the phenomena which they ob. served.
After the discovery and knowledge of the circulation of the blood, the near ques tion would naturally be about the passage and route of the nutritious part of the food, or chyle, from the bowels to the blood vessela, The name of Aselli, an Italian physician, is rendered illustrious by the discovery of the vessels which carry the chyle from the intestines. lie observed them full of a white liquor on the mysen tery of living animals, and from this cir emnstance called them milky or lacteal vessels. For many years the anatomists in all parts of Europe were daily opening living animals, either to see the lacteals, or to observe the ph:enomena of the circula tion. In making all experiment of th is kind, Pecquet, in France, was fortunate enough to discover the thoracic duct, or common mink of all the lacteals, which conveys the chyle into the subclarian vein. And now the lacteals having been traced from the intestines to the thoracic duct, and that ducthavingbeen traced to its termination 'in a blood-vessel, the passage of the chyle was completely made out. e discovery of the absorbent vessels in other parts of the body, where they are known by the name of lymphatics, from the tra.nsparent colour of their contents, very, soon follow ed that of the lacteal and thoracic duct. Rudbeck, a Swede, is generally allowed to have been the first who discovered these vessels; but this honour was disputed with him by Bartholin, a learned Dane. By these vessels the old particles of our bodies, which are no longer fit to remain in it, are removed and conveyed into the blood, to be eliminaied by the excretory' organs Leeuenhoeck tobk tip the subject of anatomical inquiry, where others had left it. Ile investigated the minute structure
of the body by- the help of magnifying glasses; and was thereby enabled to de monstrate the circulation of the blood in thc pellucid parts of' living animals; the red globules of the blood, and the animal cula of the semen were first observed by this anatomist. Malpighi also directed his attention chiefly to the development of minute structure; as that of the glands or secretory organs of the body.
About this time anatomy made two great steps, bythe invention of injections, and the method of making anatomical pre parations. For these we are indebted to the Dutch, particularly. Swammerdam and Ruysch. The anatomists of former ages had no other knowledge of the blood-ves sels, than what they could collect from la borious dissections, and from examining. the smaller branches of them upon some lucky occasion, when they were found more than commonly loaded with red blood. But filling the vascular system with a bright coloured wax, enables us to trace the large vessels with great ease, renders the smaller mucli more conspicuous, and inakes thonsands of the very minute ones visible, which, from theirdelicacy, and the transparency of their natural contents,are otherwise imperceptible. The modern art of corroding the fleshy parts with a menstruum, and of leaving the moulded W2X entire, is so exceedingly useful, and at the same time so ornamental, that it does great honour to the ingenions inventor, D r. Nichols. The m ethod of casting figures in wax, plaister, or lead, is also a g-reat ac quisition to anatomy, as it enables us to preserve a very perfect likeness of such subjects as we but seldom meet with, or cannot well preserve in a natural state. The modern improved methods of pre serving animal bodies, or parts of them, in spirits, Ws been of the greatest service to anatomy; especially in saving the time and labour of the anatomist, in the nicer dissections of the small parts of the body. For now, whatever he has prepared with care, he can preserve,. and the object is ready to be seen at any time. And, in the same manner, he can preserve anatomical curiosities and. rarities of every kind; such as parts that are uncommonly form ed; parts that are diseased ; the parts of the pregnant uterus, and its contents. Large collections of such curiosities, which modern anatomists are striving every where to procure, are of infinite service to the art; especially in the hands of teachers. They give students clear ideas about many things, which it is very essential to know, and yet, which it is im possible that a teacher should be able to shew otherwise, were he ever so well supplied with fresh subjects.