1906.] 



The Viscosity of the Blood. 



355 



investigation with serum alone he found that the addition of CO2, even to 

 saturation, produced little or no change, whilst in the. case of blood there was 

 a noticeable increase in each addition of C0 2 . This he attributed in part to 

 the swelling of the corpuscles ; his surmise was proved to be correct by 

 measuring the volume of the corpuscles by means of the hsematocrite (it was 

 found to be increased). 



Before we could make any investigation on the viscosity of the human 

 blood it was necessary to devise an instrument capable of giving results with 

 a small quantity of blood, since the instruments in use on the Continent 

 required more blood than was obtainable or even 

 permissible in this country from patients. Hirsch 

 and Beck had been experimenting with 2 cm. of blood, 

 whilst Dr. Parkes "Weber's instrument requires even 

 larger quantities of blood. Dr. Ewart had devised an 

 instrument, but it was too complicated and required too 

 many accessories for ward work. 



Fig. 10 shows the form of instrument which we 

 ultimately adopted and which is fully described in 

 Appendix I.* 



With this viscosimeter numerous observations have 

 been made upon healthy individuals with fairly constant 

 results, the average value found being roughly about 

 five times that of water. 



The following Table (VIII) contains viscosity values 

 for the blood of five men in the best of health, with a record of their 

 temperature and blood count. 



Table VIII. — A 7 iscosity Values in five Healthy People. 



Fig. 10.— Clinical Yis- 

 cosimeter for 11 «e 

 with small quantities 

 of Blood. 





Temperature. 



Blood count reds. 



Time compared 

 with water. 









98-4 



4 -000 -000 



4-82 



II 



98 -0 



5 -100 -000 



5 01 



III 



98 -6 



5 -200 -000 



5 -63 



IV 



98 -4 



5 -500 -000 



5-21 



V 



98 "4 



5 -700 -000 



5-42 



Between the highest and lowest values in this table there is a difference of 

 - 81 and if we look at the blood count it is seen, with one single exception, 



* We desire here to acknowledge our indebtedness to our colleague, Dr. Guy Barlow, 

 for much kindly help, and for the suggestion that led to our making and using this type 

 of instrument. 



