J.F. Colyer
1911 The Lancet  
293 About 1813, the year after he joined Wilson in the Windmill-street school, he made a dissection of that complex of nerves which may be exposed between the mandible above and the thorax below. He had to demonstrate them to his class next day. What explanation could he give that would account for the intricate manner in which the cranial and cervical nerves were arranged and distributed in this region ? Many of these nerves-the ninth, tenth, and eleventhdid not arise either in the line of his
more » ... in the line of his sensory or motor roots, but intermediate to them. Why was that ? He had to go to a case in the country, and on the way he discovered what he believed to be the explanation. The chief nerve of the group went to the lungs ; it was functionally therefore a respiratory nerve. The other nerves arising in line with itthe sixth, ninth, and eleventh-must also be respiratory. The muscles of the face were, in his opinion, mainly respiratory in function ; the sterno-mastoid supplied by the eleventh could be used in inspiration. He was dominated by the idea that the origin of nerves must be determined entirely by function. The mechanism of respiration, he believed, had been added to the more primary actions of the body and the system of nerves which regulated it must have been interpolated in the motor and sensory systems. He supposed that an intermediate system must be represented in the cord to influence and control the respiratory action of the body wall muscles. The phrenic (internal respiratory nerve) and long thoracic (external respiratory nerve) he also supposed to belong to this system. Bell was particularly fond of his " respiratory theory. It was the first attempt ever made to explain a certain series of complicated facts. He saw that nerves having an intermediate root origin must be different in nature from the nerves rising in the dorsal and ventral series. We had to wait 60 years before a more satisfactory explanation was given of the nerves which have an intermediate root origin. It came with the demonstration of the splanchnic system by Gaskell. But who can yet explain why the sensory system is dorsal, the ventral motor, and the intermediate splanchnic ? COMPARIS01T OF DISCOVERIES OF HARVEY AND BELL. There is a remarkable similarity between the discoveries of Harvey and of Bell. Monro, as we have seen, was puzzling over the meaning of spinal ganglia when Bell was a student in Edinburgh at the end of the eighteenth century. Fabricius was trying to explain the meaning and use of valves in the veins when Harvey was studying in Padua at the end of the sixteenth century. They were designed, Fabricius thought, to secure an even distribution of the blood during its reflux from the thorax to the extreme parts of the body. Harvey and Bell came to London to observe, reflect, and experiment, and teach and practise for a livelihood. Harvey brooded over his "new" " idea from 1616 to 1628 before publishing ; Bell over his from 1807 to 1821. Harvey found the arrangement of valves could not be explained on the current teaching of the day. They allowed blood to pass only in one direction, and that was towards the thorax. The current teaching could offerno explanation of why the lungs required a special ventricle and an artery as big as that to the whole body for their special blood-supply. No explanation was offered for the existence of the tricuspid valve, nor for the semilunar and mitral valves. Harvey was the first anatomist to formulate as a working principle for the investigator that the existence and form of every organ and part of the animal body is determined by function, and that by a study of form a key or guide may be obtained which will direct the inquirer as to the manner in which the function may be experimentally i demonstrated. A rational study of anatomy guided Harvey and Bell to their discoveries. On whatever standard one proceeds to judge, Charles Bell must be assigned a first place amongst the world's anatomists. He did for the anatomy of the nervous system what Harvey did for the circulatory system-brought order out of chaos. John Hunter was probably a greater discoverer than either, but he was an anatomist of life rather than of the human body. Harvey proved his thesis in every point ; his demonstration was complete. His inclinations were under the sole guidance of his facts. Bell, as we have seen, sometimes allowed the facts to follow his inclinations. In Bell's favour we must take into consideration he was dealing with the most complex and elusive system of the body, one which can be interrogated with success only by the more delicate modern means which Bell had not at his command. In conclusion, I cannot do better than quotd to you a footnote from Sir Charles Bell's treatise on the " Nervous System of the Human Body " : "In your department," Sir Humphry Davy said to him, 11 you can hope for nothing new. After so many men in a succession of ages have laboured on your subject, no further discovery can be expected." "This," writes Bell, "shows great ignorance of anatomy since every improvement points to something new, and the higher we go the more is the field of view extended " Once a new path is found there is no telling the various discoveries it may lead to. The path discovered by Charles Bell is one which has carried his successors into new and wide fields. Nor are the methods which Harvey and Bell employed to elucidate the human body exhausted ; those who know the structure of man best know how obscure are many parts and organs of the human body, and how indifferently they can be explained on the basis of. our current teaching. FOR several years it has been my practice to treat extensive caries in children by extraction. The principal criticisms brought against this method of treatment have been: (1) that the loss of mastication area interferes with the growth of the child ; and (2) that the effect on the permanent series is to cause irregular eruption and crowding of the teeth. I propose to show that these criticisms are not altogether supported by facts, and that the effect of the removal of the teeth on the general health of the child is beneficial rather than harmful ; still further, that the harm accruing to the permanent series is slight and well outweighed by the gain to general health. The treatment, briefly stated, consists in the removal of all functionless deciduous and permanent teeth. To consider the question more in detail. If the first permanent molars are in position the best treatment seems to be the removal of all the deciduous molars. I do not hesitate to remove sound molars if their antagonists have been removed. For example, suppose the right maxillary deciduous molars and the left mandibular molars are unsavable, and their removal is called for, then the remaining teeth-namely, the right mandibular and the left maxillary molars-are rendered functionless and can serve but little good purpose ; indeed, they will harbour food, and so prevent the mouth being kept naturally clean. It is urged that such treatment robs the child of masticating power, but such teeth are useless as far as the function of mastication goes ; indeed, they render the first permanent molars functionless, because a child with tender teeth bolts" " food and cannot chew. In cases where at, say, the age of 8 years the first permanent molars are carious and have exposed pulps or septic pulps, these teeth are removed in addition to the deciduous molars, the child being left with only the permanent incisors and the deciduous canines. The improved condition of the child following this rather drastic treatment can best be shown by detailed reference to a few cases.
doi:10.1016/s0140-6736(01)62230-x fatcat:3ck6ngwbprd2res6o4b6ecfxie