304- Royal Society. 



notices, in case the annual change shall prove to be diminishing in 

 this part of the world, the importance of determining the precise 

 period at which the dip shall become stationary, and the minimum 

 to which it shall then have arrived. 



Jan. 15. — "Observations relating to the Function of Digestion." 

 By A. P. W. Philip, M.D. F.R.S., &c.— The author, referring to his 

 former papers, published in the Phil. Trans, concludes, that diges- 

 tion requires for its due performance, both a proper supply of 

 gastric secretion, and a certain muscular action in the stomach ; 

 the latter circumstance being needful for the expulsion of that por- 

 tion of food which has been acted upon by the gastric juice. Ner- 

 vous power is necessary for secretion ; but the muscular action of 

 the stomach being excited by the mechanical stimulus of the con- 

 tents of that organ, is independent of the nervous power. It had 

 already been shown by the author, that after the removal of a por- 

 tion of the eighth pair of nerves, the galvanic influence directed 

 through these nerves will restore the secretion of gastric juice. But 

 Messrs. Breschet and H. Milne Edwards have lately endeavoured 

 to prove that the same effect results also from mechanical irritation 

 of the lower portions of the divided nerves. The author points out 

 several circumstances which appear to have been overlooked by 

 these gentlemen, and which he thinks invalidate the conclusions 

 they have deduced from their experiments. He states that a cer- 

 tain quantity of digested food will always be found in the stomach 

 of the animal for five or six hours after the operation, and even after 

 the lapse of ten or twelve hours, from its being less completely 

 changed, and therefore expelled more slowly than in the natural 

 state. The paper concluded with the recital of experiments made 

 for the author by Mr. Cutler, in which the contents of the stomach 

 of a rabbit, whose eighth pair of nerves, after excision, had been 

 kept mechanically irritated, were compared with those of another 

 rabbit in which the nerves had not been irritated, and of a third 

 which had been left undisturbed. All those who witnessed the re- 

 sult of this experiment, among whom was Mr. Brodie, were con- 

 vinced that the irritation of the nerves had no effect whatever in 

 promoting the digestion of the food, neither did it at all contribute 

 to relieve the difficulty of breathing consequent upon the section of 

 the nerves. 



Jan. 29. — A paper was read " On a definite Arrangement, and 

 Order of the Appearance and Progress of the Aurora Borealis; 

 and On its Height above the Surface of the Earth ;" by the Rev. 

 James Farquharson, minister of the parish of Alford, in Aberdeen- 

 shire. Communicated by the President. 



The results of the numerous observations of the author on the 

 aurora borealis, which on several occasions were made under very 

 favourable circumstances, had already been announced in a short 

 paper published in 1823 in the Edinburgh Philosophical Journal; 

 and it was concluded from them that the aurora borealis has in all 

 cases a determinate arrangement and figure, and follows an inva- 

 riable order in its appearance and progress ; that the pencils of rays 



I 



