On Commerce, 267 



the fauces, trachea, he. bears a much larger proportion to 

 the whole mass respired, than when the inspirations are deep. 



7. No hydrogen, nor any other gas, appears to be evolved 

 during the process of respiration. 



S. The general average of the deficiency in the tolal 

 amount of common air inspired, appears to be very small, 

 amounting only to about 6 parts in 1000, and we are in- 

 clined to attribute it in great measure to the difficulty in ex- 

 hausting the lungs as completely after an experiment as be- 

 fore it ; the first expiration being made into the open air a 

 the last into the apparatus. 



9. The experiments upon oxygen gas prove that the quan- 

 tity of air remaining in the lungs and its appendages is very 

 considerable, and that, without a reference to this circum- 

 stance, all experiments upon small quantities of gas are 

 liable to inaccuracy. 



Other important conclusions might perhaps be drawn from 

 the facts related in this paper : but having already trespassed 

 largely upon the time of the Society, we shall abstain from 

 any further remarks, until we bring forward a new series of 

 experiments. 



XXXIX. On Commerce. By Mr. James Gp.aham, of 

 Berivick-upon- Tweed* 



To Mr. Tilloch. 



SIR, 



-T rom some circumstances needless to mention, I did not 

 see your Magazine till a few days ago, in which some re-? 

 marks are made on my Essay on Commerce. 



Before I again enter upon this subject, permit me to re-? 

 turn my best thanks to Mr. Lapis, for the mild and candid 

 manner in which he has offered his remarks. I am much 

 ■obliged by his giving me an opportunity of further illus* 

 trating and proving the propositions I laid down in my for- 

 mer Essay ; but after all, if it should appear that some of 

 my opinions were erroneous, the sooner my error is detected 



the 



