SALUTARY EFFECTS OF GESTATION. 29/ 



Part IU. On the salutary Effects of Riding , and other Modes 

 of Gestation. 



In the preceding instances of disturbing the circulation Gestation 

 of the blood by external motion, the effect is disagreeable, 

 and proportionally prejudicial. There may indeed be cases 

 of disorder, in which it will be salutary ; but these are pro- 

 bably less frequent, than is generally supposed, 



lu the observations which follow, general opinion will 

 concur with me, on the benefit derived from external or pas- 

 sive motion ; and 1 hope, that, in ascribing its good effects 

 to their true cause, I shall enable others to make a valuable should be dis* 

 distinction, which has not yet been preserved with due care, j-J.^^^ exercise 

 between one motion which is salutary, and another which is in general ; 

 very frequently pernicious. For, although the term gestation 

 is employed by medical writers, as a general term compre- 

 hending riding on horseback, or in a carriage; and although 

 the merits of such motions, especially the foraier, were 

 cle-irly noticed, and perhaps even overrated, by the discern- 

 ment of Sydenham ; I believe, that no explanation has yet ^ 

 been given of the peculiar advantages of external motion, 

 and am persuaded, that the benefits to be derived from car- 

 riage exercise are by no means in so high estimation as 

 they ought to be. 



Under the common term exercise, active exertion has too active being 

 frequently been confounded with passive gestation, and fa- ^here^passive 

 tiguing efforts have consequently been substituted for mo- is salutary. 

 tionsthat are agreeable, and even directly invigorating, when 

 duly adapted to the strength of the- invalide, and the pecu- 

 liar nature of his indisposition. 



1 he explanation, which 1 am about to offer, of the effects EfFects of ges- 



of external motion upon the circulation of the blood, is '^^"'? °'^ "^^^ 

 ^ ' circiilannn or 



founded iipon a part of the structure observable in the ve- the blood, 

 npus system, the mechanical tendency of which cannot be 

 doubted. The valves, which are every where dispersi^d 

 through tho?e vessels, allow free passage to the blood, wlien 

 propelled forward, by any motion that assists its progress; 

 but they oppose an immediate obstacle to such -.m have a 

 contrary tendency. The circulation is consequently helped 

 fqrward by every degree of gentle agitation. The heart iji 



supported 



