Atkins — Osmotic Pressures of the Blood and Eggs of Birds. 125 



Vigorous ami continued stirriug is neoessai-}' in all work with sucli viscous 

 fluids as blood and eggs. 



Materials used. 



The blood examined was obtained from the neck of the bird, and drained 

 into a clean dr_y bottle, which was then corked, and sent to the laboratory. 

 The whole blood was used, both the serum and the contents of the clot. The 

 specimens were examined as soon as possible ; but standing for two days in a 

 cold room in winter was found to produce no alteration. Putrefaction, 

 however, alters the freezing-point, increasing the number of molecules by 

 the breakdown of complex into simpler ones, and by disintegration of the 

 red corpuscles. The blood was always in the arterial condition when 

 examined, being saturated with oxygen by the constant stirring. 



The eggs used were perfectly fresh, and were broken and drained direct 

 into the inner tube. No difference was found in the freezing-point of the 

 white and yolk of the same egg, and a mixture of white and yolk gave the 

 same depression. Accordingly, in all the experiments recorded, the white of 

 the egg was employed, as it was much easier to stir than the yolk. The 

 results obtained are tabulated below. 



Common Fowl {Gallus hanhiva). 



y2 



