124 EIGHTH REPORT — 1838. 



Experimental Investigation into the Functions of the Eighth Pair of 

 Nerves. By Dr. J. Reid. 



This communication Avas a continuation of the paper which the au- 

 thor laid before the last meeting of the Association, and was chiefly- 

 confined to the functions of the gastric and pulnionary branches of the 

 nervus vagus. 



From a great number of experiments upon the effects of division of 

 the nervus vagus, it was observed that no dyspnoea was induced, if a 

 sufficient quantity of air reached the lungs, and that the only constant 

 and invariable effect of division of both vagi nerves was a great dimi- 

 nution in the frequency of the respiratory movements. Though the 

 nervus vagus is, however, the principal exciter of the respiratory move- 

 ments, it is not the sole nerve which transmits to the medulla oblon- 

 gata the impressions which excite the movements of I'cspiration ; for in 

 several experiments performed to ascertain this point, the respiratory 

 movements continued (though much diminished in frequency) after 

 the remo^'al of the hemispheres of the cerebrum and the lobes of the 

 cerebellum, and the division of the vagi and recurrent nerves. Dr. Reid 

 believes that all the morbid changes observed in the lungs after death 

 are to be explained by the effects of the diminished frequency of re- 

 spiration. 



Several experiments were related to prove that digestion is not neces- 

 sarily arrested after division of the vagi. These appeared satisfactory 

 to Drs. Alison, Knox, and others who witnessed them. 



Experiments were related to prove that narcotic poisons produce 

 their deleterious effects as rapidly when injected into the stomach after 

 the division of the vagi as when these nerves are left entire. 



Experin.ents were brought forward to show that division of the vagi 

 nerves previous to the introduction of a poisonous dose of arsenic into 

 the system, does not arrest the usual mucous and watery secretions 

 from the inner surface of the stomach and intestines. 



The results of a great number of observations were stated to prove 

 that the contraction of the pupil, and the half-closed state of the eye- 

 lids, which accompany section of the vagi in those animals in which 

 the sympathetic is intimately conjoined with the vagus, are not the re- 

 sult of the inflammation of the conjunctiva, but are independent of this 

 circumstance. 



On the Beneficial Effects of Mercurial Action rapidly induced, more espe- 

 cially in certain forms of Neuralgic Disease . By T. M. Greenhow, 

 one of the Surgeons to the Newcastle Ijifirmary. 



The purpose of this paper is to show the greater safety and efficiency, 

 in many forms of disease, of introducing into the system such quanti- 

 ties of calomel combined with opium, in repeated doses, as will secure 

 the early production of the specific action of this medicine, as evinced 

 by tenderness of the gums. 



