V. 



THE STRUCTURE OF COLOEED BLOOD- 

 CORPUSCLES. 



BY Louis ELSBERG.* 



THE discovery of red corpuscles in the blood was one of the 

 first results of microscopical study, over two hundred years 

 ago. Since that time no other constituent of the body has been 

 more frequently examined. Nevertheless, the structure of col- 

 ored blood-corpuscles has not heretofore been ascertained. 



The examination of a small drop of fresh human blood, mixed 

 with a drop of from 40 per cent, to 50 per cent, saturated solu- 

 tion of bichromate of potash, and highly magnified,! reveals in 

 the, course of a few hours the following : 



Perhaps the first thing noticed is that the colored corpuscles 

 vary in size. 



* " Annals of the New York Academy of Sciences," vol. i., 1879. 



t My investigations were made with a jV immersion objective, manu- 

 factured by Tolles, of Boston, and a No. 12 immersion made by Verick, of 

 Paris, either of which, with the eye-piece that was used, magnifies about 1000 

 times. An exceedingly thin cover having been oiled near the edges, the drop 

 of blood obtained from a pin-prick in the palm of the hand, and transferred 

 on a slide, is mixed with a drop of the solution previously prepared, covered, 

 and without delay placed on the microscope stage. By a 50 per cent, satu- 

 rated solution, I mean a saturated solution diluted with an equal quantity of 

 distilled water; by a 40 per cent., one containing three-fifths water; by a 

 60 per cent., one containing two-fifths water, etc. : I always prepare a sat- 

 urated solution, and then dilute. 



