1906.] 



The Viscosity of the Blood. 



331 



F. Lommel observed the influence of sweating upon the viscosity of the blood 

 and found, as might have been expected, that in the great majority of cases 

 the viscosity increases owing to the loss of water.* 



A. Mayer, in 1901, calculated the coefficients of viscosity of serum, and of • 

 normal blood plasma in certain mammals, including man.f 



G. Eossi, repeating and extending the observations of Burton-Opitz and 

 A. Mayer, noted the influence of temperature of the viscosity of blood serum. 

 He remarks upon a rather sudden change about the temperature of 45° C, and 

 which is revealed by a marked diminution in the rate at which the viscosity 

 declines and the electrical conductivity is at the same time increased.^ 



Fano and Kossi, as a result of their investigations on liquid organic 

 colloids, classify them in two groups according to their behaviour when certain 

 substances as glucose, sodium chloride, etc., are added : in the one group, in 

 which are placed such bodies as gum and starches, the viscosity is considerably 

 diminished by these additions, whereas in the other group, in which are the 

 albumens and various sera, but little effect is produced. However, after 

 subjecting serum to dialysis they found on again adding the above substances 

 that the mixture behaved like a solution of gum or starch ; on the other hand, 

 if the dialysed material were added to a solution of a gum, this conducted itself 

 as the original serum.§ 



Again Fano and Kossi have confirmed Burton-Opitz's observation as to the 

 influence of the thyroid on the blood. Experimenting on dogs and rabbits 

 they found that the removal of the thyroids alone brought about some slight 

 increase in the viscosity ; but when the parathyroids also were removed, the 

 viscosity rapidly increased to the time of death, which ensued sooner or 

 later. They assume, therefore, that these bodies produce an internal 

 secretion which is of the nature of an enzyme, whose function is to adjust the 

 chemico-physical conditions of the blood, or, in other words, to regulate the 

 viscosity.|| 



C. Ferrai drew attention to the marked increase in the viscosity of the 

 blood in asphyxia. He found that it may become double that of arterial 

 blood, and increases in proportion to the increase of C0 2 . One element in 

 this increase may be the swelling of the corpuscles under the influence 

 of CO, since the addition of C0 2 to serum, even to saturation, does not 

 increase its viscosity.1T 



* F. Lommel, ' Deutsch. Arch, f iir Klin. Med.,' vol. 80, p. 830. 



t A. Mayer, ' Comp. Eend. de la Soc. de Biol.,' vol. 53, p. 1138, and vol. 54, p. 367, 1904. 



\ G. Eossi, 'Arch, di Fisiol.,' vol. 1, p. 500. 



§ Fano and Eossi, ' Arch, di Fisiol.,' vol. 1, p. 609, 1904. 



|| Fano and Eossi, 'Arch, di Fisiol.,' vol. 2, 1905. 



IT C. Ferrai, 'Arch, di Fisiol.,' vol. 1, p. 305, 1904. 



