664 Mr. J. Rice on the. Form assumed 



have therefore to proceed to the next test, as explained 

 above, to obtain a more consistent theory. 



The considerations here offered are necessarily of a pro- 

 visory nature, and many of the really fundamental difficulties 

 involved in them have necessarily been merely cursorily 

 reviewed. They are, however, put forward in their present 

 form in the hope of stimulating further discussion of these 

 difficulties, with the object of ultimately obtaining a con- 

 sistent formulation of the central problem. It is held that, 

 in reality, no difficulties of a fundamental nature underlie 

 the theory, and that no implications are contained in it of 

 any new physical basis for the phenomena of radiation. 



The University, Sheffield, 

 June 21, 1914. 



LXIX. Note on the Form assumed by the Red Corpuscles 

 of the Blood, or by the Suspended Particles in a Lecithin 

 Emulsion. By J. Rice, M.A., Lecturer in Physics, 

 Liverpool University * . 



IT is well known that on examination by a microscope, a 

 small drop of blood is seen to be composed of a multitude 

 of corpuscles floating and rolling over and over in the minute 

 eddies of a fluid — the plasma. The great majority of these 

 corpuscles are coloured, and on close examination these are 

 found to have the shape of a disk cupped on both surfaces — 

 a biconcave disk with rounded edges. If lecithin is shaken 

 up with water, in the emulsion thus formed will also be 

 found minute particles having a similar shape. Measure- 

 ment reveals the fact that the diameters of these disks are 

 from 5 to 10 fi; their thickness at the centre eludes accurate 

 measurement owing to diffraction patterns, but is undoubtedly 

 very small. When viewed edge-on, a " diametral section " 

 of these little floating bodies would have the appearance of 

 a dumbbell, and it is striking that they should preserve this 

 shape, and not adopt the spherical shape, which is that com- 

 monly assumed by drops of one liquid floating in another of 

 the same density. If water be added to the blood, water 

 enters the red corpuscles and causes them to become globular 

 and then burst; if a strong solution of salt be added, water 

 leaves the corpuscles, which become shrivelled; these ex- 

 periments indicate that each corpuscle is surrounded by a 

 film. Now it is a natural assumption that the extreme thin- 

 ness of the little disks at their centre produces such a change 



* Communicated by Prof. L. R. Wilberforce. 



