PROBLEMS OF MODERN SCIENCE 



frequently during the recent war ? Shock is very 

 often due to loss of blood. How is the person 

 to get on without blood ? You cannot always get 

 human blood. You cannot always get the friend, 

 the heroic friend, who will give his blood to save 

 his brother, and you must not use the blood of cats 

 and dogs and cows and sheep, because then the 

 remedy will be worse than the disease. And even 

 when you can get the hero to step forward and give 

 his blood for his friend, the donor must be very 

 carefully selected, and a blood relation, if possible, 

 should be chosen. Well, at the front there were 

 comparatively few soldiers, I suppose, who had 

 relatives at hand who could let their blood be tapped 

 and thrown into these men's vessels, and, as a 

 makeshift, it was found that the injection of a 

 solution of salt would produce temporary relief, 

 because it would increase the blood-volume and 

 enable the comparatively small number of red 

 blood-corpuscles, the oxygen-carriers, to do their 

 work until more had been formed to carry it on. 

 It was found, however, that the effect was only 

 temporary, because the saline fluid leaked out 

 almost as quickly as it was thrown in, until Bayliss, 

 knowing the colloid properties of the blood itself, 

 which resemble very much those of the various 

 colloids he had been investigating, suggested mixing 

 with the saline fluid some gum. He was able to 

 do this with perfect confidence, and as a result the 

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