II «-) \H»\ IMIM >n I 111 



will be equal to thai done in raising thi 

 heighl ponding t" the mean pr< 



millimeters of mercury, which would i 

 column "t* blood 1,755 meters high l " IT".", nun l> 



meter , tin- work «l<>n.- I>v th<> lefl ventricli 

 kilogram-meters in one minute, or in tw< Four h< 



00 kilogram meters. The v. ork done by the rigl 

 about one-third thai of the left, this being aboul tin 

 sures in the two chambers The total work of the I 



■ aboul 14000 kilogram meters This pep Is an enormoi 



of work; indeed it has been computed that it is 

 of 70 kilograms to aboul twice the heigl 

 v York. The work thus expended in forci 

 capillaries 1 omes converted 1>.\ friction in the small bl 



•. the heat equivalent of the above amount of work tx 



aboul 350 color 1 



THE CIRCULATION TIME 



The circulation time, or the time taken by a drop of bl 1 



between two points in the circulation, can n labo I 



animals by a variety of methods, all depending on the pri 

 how long it takes for a drop of Borne substance injected into an 

 appear in the corresponding vein. For example, to determine tl 

 taken for a drop of blood to pass from the jugular vein int< 

 artery in a rabbit, a solution of methylene blue in isotonic saline is in- 

 jected into the former vessel and the moment i 

 tin- walls of the artery determined b) a stop-watch. It" the walls , 

 thick to admil of the employmi this method, a \ iolution 



sodium chloride may be substituted for the methyleni 

 ment of its appearance at another poii lulation d< I 



ing tl itrical conductivity of the 



ductivity of a blood v< la partly on I 



trolytes in the blood flowing through it. tin- mon 

 solution, appears will be ind I b\ a 



I ' 



1 1 ich methods, it has I.. • ,ml tl 



circulation is ven short compared with that of tl 

 In a rahl.it it is usually a little less than I 



• 1 dog of about 12 kil 

 it is computed to 1"- about I 



filiation tiiin> iii BUcIl 



