r 123 ] 



XIII. 



THE OSMOTIC PRESSURES OF THE BLOOD AND EGGS OF 



BIRDS. 



By W. R. GELSTON ATKINS, B.A., 

 University Chemical Laboratory, Trinity College, Dublin. 



[cOMMUNlCATiSD BY PROFESSOR H. H. DIXON, SCO., F.R.S.] 



[Read March 23. Received for Publication ApiiiL 6. Published May 28, 1909.] 



While the relation between the osmotic pressures of the blood or body- 

 fluids of marine and fresh- water vertebrates and invertebrates and that of the 

 surrounding medium has been studied by many workers, notably by 

 Bottazzi, Garrey, Rodier, Greene, and Dakin ; and while the blood of 

 mammals has been examined by Dresser, Koranyi, Hamburger, and others, 

 the blood of birds has been quite neglected, as far as I am aware, except for 

 three determinations of the osmotic pressure of the blood of the common fowl, 

 Gallus baiikiva, by Hamburger, and three by Grijins. This may be 

 accounted for by the fact that the study of the blood of birds apparently 

 affords no question of interest comparable to the equilibrium maintained 

 in water-dwelling organisms. Tlie attractiveness of the study of the 

 osmotic forces in land animals lies in the equilibrium between the various 

 body fluids and between the same fluids at various times. 



The work of Koranyi, Bousquet, Kummel, and the great mass of 

 literature on the normal constancy and pathological variations in human 

 blood, and the relation between the osmotic pressures of the blood and urine, 

 bear witness to the great importance of this brancli of the subject. 



It seemed likely, however, that the relation between the osmotic pressures 

 of the blood and eggs of birds might be of interest ; so the study was begun, 

 but difficulty in obtaining the requisite materials delayed it, and still 

 prevents its completion. The method adopted was the usual one — the 

 determination of the freezing-points of the various liquids. 



Technique of freezing-point Determinations. 



The apparatus used was the ordinary Beckmann with thermometer 

 graduated in hundredths of a degree ; tenths of a scale-division were 



SCIENT. PBGC. E.D.S, VOL. XII., NO. XIII, Y 



