300 REPORTS 01* THE STATE OF SCIENCE. 



But the revised passage now has below it the following footnote 

 which, while hardly of an explanatory nature, shows that the alteration 

 had not been regarded as insignificant either by Bell or by his critics : — 



' The reader is referred to the next paper (on the facial nerves — " Phil. 

 Trans.," 1829) and the explanation of the plates for the more minute anatomy 

 of this nerve. I have often been requested in vindication of the correctness 

 of my original account of the fifth nerve to report my early statement of the 

 uses of this nerve. I can give nothing more distinct than in this passage, and 

 I suepect that mistakes on this point have been encouraged and propagated in 

 consequence of the limited circulation of this work in its first expensive shape 

 of publication.' 



On p. 5 of the preface to this edition Bell says : — 



' Eight papers were in succession printed in the Royal Society's " Trans- 

 actions." It would be a great labour to recast the whole of these so as to present 

 them in a strictly systematical form; and, if not misled by the partiality of 

 friends, the author believes that the observations will be more acceptable in their 

 original form.' 



Bell's Figures of the Fifth Nerve in 1821 and 1824. — The figure and 

 its explanation are altered in 1824 to correspond to the altered text. 

 In 1821, p. 423, as regards the three divisions of the fifth the explana- 

 tion of Plate XXX. is as follows : — 



B. — The frontal division of the trigeminus or fifth nerve. 



C. — The infra-orbital division of the same fifth nerve. This branch is large 

 and its sub-divieions form a plexus before finally dividing to supply the muscles 

 of the nostril and lip. 



D. — The third grand division of the fifth nerve, or mandibulo-labialis, to the 

 muscles and integuments of the chin and lower lip. 



In 1824, at p. 143, the original plate is replaced by a simplified 

 diagram, Plate III., and the explanation is amplified by the following 

 paragraph : — • 



' In this plate the two distinct classes of nerves which go to the face are 

 represented, the one to be#ow sensibility, and the other for motion, and particu- 

 larly for the motions of speaking and expression — that is, the motions connected 

 with the respiratory organs. 



' The nerves on the side of the neck are also represented. These I have dis- 

 covered to be double nerves, performing two functions ; they control the muscular 

 frame and bestow sensibility on the skin. . . .' 



This paragraph, added in 1824 without acknowledgment to the 

 republished paper of J 821, constitutes the first explicit statement pub- 

 lished by Bell of a distinction between motor and sensory nerves. 



It passes on without acknowledgment into the subsequent editions 

 of 1830 (Plate VI., clxiii.), and of 1836, 1844 (Plate VI., p. 464). 



In 1824 the explanation of the plate as regards the fifth nerve is as 

 follows : — 



I. — Frontal nerve, a branch of the fifth. 

 II. — Superior maxillary nerve, a branch of the fifth. 

 III. — Mandibulo-labialis, a branch of the fifth. 

 V. — Temporal branches of the second division of the fifth. 



