NOTICE OF THE LATE SIR CHARLES BELL. 401 



The more obscure vessels called lacteals and lymphatics, altogether eluded 

 the observation of ancient anatomists. The existence of the lacteals was dis- 

 covered accidentally, and their functions were partly conjectured by ASELIUS of 

 Pavia, a cotemporary of HARVEY ; and their office, that of conveying the nutritive 

 part of the food from the intestines to mingle with the blood, and thus to be 

 distributed to all parts of the body, was demonstrated by PECQUET, a French 

 anatomist, who had also the candour to acknowledge that his discovery was ac- 

 cidental. The lymphatics were shortly afterwards discovered by RUDBECK and 

 by BAETOLINE, the one a Swede, the other a Dane, who shrewdly suspected what 

 their functions were ; and the subject was further illustrated, and the functions 

 of these vessels fully explained, by the late Mr HUNTER and the late Dr MONRO, 

 who proved them to be absorbents, that is, the vessels by which the waste of the 

 body, which the lacteals supplied new matter to replace, was carried off. 



It is worthy of remark, that both these offices had been assigned to the veins, 

 which, as we have seen, were also, at one time, regarded as the only blood-ves- 

 sels ; and although the manner in which the work of absorption is divided be- 

 tween the lymphatics and the veins is still somewhat obscure, yet the constant 

 result of these successive discoveries has been to shew, that the function of each 

 portion of these vessels is simpler than it had been supposed to be ; and that na- 

 ture perfects the performance of the animal functions, by multiplying the organs 

 and simplifying the duties of each, rather than by simplifying the general struc- 

 ture, and complicating the functions of its parts; and we shall find that the 

 nerves afford a further illustration of this principle.* 



The nerves had been noticed from the earliest times, and their functions were 

 long known to be to transmit the mandates of the will from the brain, which has 

 always been regarded as the sensorium, to all the parts which are under the con- 

 trol of the will ; and to communicate to the sensorium, intelligence of the condi- 

 tion of their own extremities, which we call sensation. They were divided by 

 anatomists into cranial and spinal or vertebral nerves, with reference to their 

 origin from the brain or the spinal marrow. 



In the same manner as it had been taught before the discoveries of HARVEY, 

 that there was a flux and reflux of the blood in the arteries and the veins ; that 

 it flowed " backwards and forwards like the tide of Euripus ;" so it was taught in 

 our own days, that the same nerves transmitted the mandate of the will from the 

 sensorium to the organs of voluntary motion, and likeAvise carried to the senso- 



* Another general fact, which seems to be well ascertained, may be referred to the operation of the 

 same principle, and, in this respect, has also some analogy to the great discovery of Sir CHARLES BELL 

 in regard to the nerves, viz., that different portions of the small arteries, which are similar in size, struc- 

 ture, and degree of subdivision, have nevertheless very different relations to the blood which they carry, 

 and suffer very different portions of that blood to transude through their coats, so as to maintain the 

 functions of secretion and nutrition ; thus affording another instance of the natural subdivision of labour. 

 VOL. XV. PART III. J5 Q 



