20 



ANNALS NEW YORK ACADEMY OF SCIENCES 



are so many and to such a degree unknown, that although, in the final 

 analysis, the phenomena must be physical and chemical, we are not justi- 

 fied in maintaining that the relations are definitely quantitative. 



Figure 3 represents in a graphic manner the relation of the osmotic 

 pressure of the blood to the concentration of the external medium as 

 based upon the conception of a proportional relation existing between the 

 two. The abscissas represent freezing point determinations. The ordi- 

 nates represent specific gravities of difl^erent solutions of sea-water. Pure 



-1.00 



-1.50° 



-2.00'= 



-2.50" 



Fio. 3. — Relation of the A of hlood to A of different solutions of sea-water. 

 A-B = A's of solutions. Curve C-D = A's of Mood 



Curve 



water has a A of 0.00° and a specific gravity of 1.000. The curve A — B 

 represents the freezing point of different dilutions of sea-water. This 

 curve is constructed from freezing point data obtained from seven differ- 

 ent dilutions of sea-water. These were as follows : I, pure water ; II, three- 

 fourths pure water plus one-fourth sea-water; III, one-half pure water 

 plus one-half sea-water; IV, one-fourth pure water plus three-fourths 

 sea-water; V, sea-water; VI, concentrated sea-water having a specific 

 gravity of 1 .030 ; VII, concentrated sea-water having a specific gravity of 



