DERATION OF Muscular action, 



so that the vessel may easily be taken out, to be cleaned or 

 weighed, 



E the cover, to ^X'hich the glass stopple is cemented. It 

 is here seen closed by the position given to the counterpoise 

 Ff which is secured by the pressure of the catch g, in the 

 movable part of the counterpoise H, on the elbow in the 

 handle. 



VII. 



The Croonian Lecture. S^ William Hyde WoLLAStoN, 

 M.D. Sec,R.S* 



JL AM aware that the remarks, which I have to offer on the Croonisji 

 present occasion, may be thought to bear too little direct ^^'^^"f^- 

 relation to each other for insertion in the same lecture ; yet 

 any observation respecting the mode of action of voluntary 

 muscles, and every inquiry into the causes which derange, 

 and into the means of assisting the action of the heart and 

 blood vessels, must be allowed to promote the design of 

 Dr. Croone, who instituted these annual disquisitions^ 

 And it has always appeared to be one great advantage at- Ons of the ad- 

 tending the labours of this society, that it favours the pro- vantaoes of 

 duction of any original knowledge, however small, in a 

 detached form ; and enables a writer to say all that he 

 knows upon a particular subject, without inducing him to 

 aim at the importance of a long dissertation. 



I shall therefore make no apology for dividing the follow- Subjects oT 

 ing lecture into three distinct parts. thispapar. 



In the fifstof which I shall treat of the duration of v6lun- 

 tary action. 



In the second, I shall attempt to investigate the origin of 

 seasickness, as arising from a simple mechanical cause de- 

 ranging the circulation of the blood. 



In the third, I shall endeavour to explain the advantoge 

 derived from riding and other modes of gestation, in assist- 



* Philoi. Tr.ins. for 1810, p. J. 



Vol. XXVII.— Dec. 1810. U in^f 



