GLASS II. 1. 1. 4. OF SENSATION. 153 



them, into too great action, and might thence injure the sense 

 of smell which is diffused on it. 



In this operation the too great action of the vessels of the 

 membrane of the nostrils is the remote cause ; the sensation 

 thence induced is the proximate cause; and the muscular ac- 

 tions are the proximate effect. 



This action of sneezing frequently precedes common respira- 

 tion in new-born children, but I believe not always; as like the 

 latter it cannot have been previously acquired in the uterus. 



It is produced in some people by sudden light, as by looking 

 up at the sky in a morning, when they come out of a gloomy 

 bed-chamber. It then becomes an associate action, and belongs 

 to Class IV. 1.2. 2. 



M. M. When it is exerted to excess it may be cured by 

 snuffing starch up the nostrils. See Class I. 1. 2. 13. 



4. Mietitus. Panting. The quick and laborious breathing 

 of running people, who are not accustomed to violent exercise, 

 is occasioned by the too great conflux of blood to the lungs. As 

 the sanguiferous system, as well as the absorbent system, is fur- 

 nished in many parts of its course with valves, which in general 

 prevent the retrograde movement of their contained fluids; and 

 as all these vessels, in some part of their course, lie in contact 

 with the muscles, which are brought into action in running, it 

 follows that the blood must be accelerated by the intermitted 

 swelling of the bellies of the muscles moving over them. 



The difficulty of breathing, with which very fat people are 

 immediately affected on exercise, is owing to the pressure of the 

 accumulated fat on the veins, arteries, and lymphatics; and 

 which, by distending the skin, occasions it to act as a tight ban- 

 dage dn the whole surface of the body. Hence when the mus- 

 cles are excited into quicker action, the progress of the blood in 

 the veins, and of the lymph and chyle in the absorbent system, 

 is urged on with much greater force, as under an artificial ban- 

 dage on a limb, explained in Art. IV. 2. 10. and in Sect. 

 XXXIII. 3. 2. Hence the circulation is instantly quickened to 

 a great degree, and the difficulty of breathing is the consequence 

 of a more rapid circulation through the lungs. The increased 

 secretion of the perspirable matter is another consequence of this 

 rapid circulation; fat people, when at rest, are believed to per- 

 spire less than others, which may be gathered from their generally 

 having more liquid stools, more and paler urine, and to their 

 frequently taking less food than many thin people; and lastly, 

 from the perspiration of fat people being generally more inodo- 

 rous than that of lean ones; but when corpulent people are put 

 in motion, the sweat stands in drops on their skins, and they 



VOL. ii. x 



