344 Dr. A. du Pre Denning and Mr. J. H. Watson. [May 7, 



and (C) respectively — the number of corpuscles being given by the side 

 of each curve. The differences in slope obviously form a graphical con- 

 firmation of the foregoing remarks with regard to the temperature coefficient, 

 whilst the numerical details supplied in the tables show that it ranged from 

 about - 0002 to O004. Although the temperature gradients are represented 

 by straight lines in these diagrams, experiments over a larger range showed 

 that the change of viscosity with temperature was by no means a linear 

 function. 



40° 











3 % Pot. Ox. 



'5% Sod. Git. 



u 



\\ 

 l\ 

 \k 









% 





l\ 

 u 

 \\ 



<tl\ 



iSi\\ 



-A 





— — 









\\ 













+ 





•OIO -OI5 -020 -025 -03O -035 -040 



Viscosity Coefficients 



Fig. 8. — Curves contrasting Temperature Variations after Additions of Potassium Oxalate 

 and Sodium Citrate solutions respectively. (Cf. Table III [A] and [C].) 



The Effect of Added Salts, etc. — The possible influence which the addition of 

 salts may have upon the relation of the viscosity to the number of corpuscles 

 will have already been gathered both from the tables of numerical results 

 and from the curves, of which mention has so far been made. From fig. 5 it 

 will appear that the addition of 03 per cent, potassium oxalate reduced the 

 viscosity coefficient of blood containing 8 - 4 x 10 s corpuscles per cubic 

 millimetre to less than half of that with blood containing 0*1 per cent, 

 potassium oxalate, but otherwise similar in composition ; whereas from fig. 6 

 the difference caused by the added salts is hardly noticeable with the three 

 anti-coagulators mentioned in the figure. Again, fig. 8 would apparently 

 indicate that 0"3 per cent, potassium oxalate could evidently reduce the 

 viscosity more than 05 per cent, sodium citrate, whilst the mean temperature 

 coefficient would seem to be larger for the sodium citrate solution, inasmuch 

 as the potassium oxalate temperature curves are steeper. 



Although it is evident in the cases just considered that the addition of 



