THE BLOOD AND THE BLOOD-FORMING ORGANS. 383 



Saturated aqueous solutions of 



Orange G 13 to 14 c.c. 



Acid f uclisin 6 " 7 " 



Methyl green 12.5 



To the mixture of these add 



Water 15 c.c. 



Absolute alcohol 25 " 



Glycerin 10 " 



The specimen should be stained in this fluid for three to five minutes, washed in dis- 

 tilled water, dried, and mounted in dammar dissolved in xylol. 



The red cells are then found stained orange-yellow, the nuclei dark-green or blue, 

 the neutrophile and eosinophile granules dark-red. The mast-cell granules are not 

 stained. 



Rather more uniform results, especially as regards the red cells, may be obtained 

 by the following method, which also demonstrates the malarial plasmodium and baso- 

 phile granules, but not the neutrophile granules: Place the specimens for two minutes 

 in a saturated alcoholic solution of eosiu, wash in water, and counterstain for five 

 minutes in a one-per-cent watery solution of methylene blue. The red cells and eosino- 

 phile granules then appear bright-red. The nuclei, basophile granules, and malarial 

 piasmodia are stained blue. 



Recently a stain has been devised by Jenner which bids fair to supplant other 

 methods on account of its simplicity, rapidity, and ease of application. It consists of a 

 half-per-cent solution in methyl alcohol of a compound made by mixing a 1.2 per cent 

 aqueous eosin and a one-per-cent aqueous methylene-blue solution. The precipitate 

 which forms is filtered off, washed with distilled water, dried, and dissolved in the 

 methyl alcohol. The blood smears are fixed by this solution in from one to three minutes. 

 The red cells are of a terra-cotta color, the nuclei blue, the neutrophile and eosinophile 

 granules red, the mast-cell granules purple; bacteria, malarial organisms, and blood 

 plaques blue. 



For the demonstration of fat in blood from a finger prick, cover-glass preparations 

 dried in the air should be stained for twenty-four hours in one-per-cent aqueous solu- 

 tion of osmic acid. To avoid numerous sources of error, a control preparation should 

 be previously placed in chloroform for twenty-four hours to dissolve the fat, and two 

 specimens carried together through the osmic acid. In the one, black fat droplets will 

 be seen, which should be entirely absent in the other. 



FOREIGN BODIES IN THE BLOOD. 



Various bodies which do not belong there, aside from those above 

 mentioned, may find access to the vessels and mingle with the blood. 

 Pus cells may get into the blood from the opening of an abscess into a 

 vessel or from some inflammatory change in its walls. Desquamated 

 endothelial cells from the vessel walls, either in a condition of fatty de- 

 generation or in various stages of proliferation, may be mingled with the 

 normal blood elements ; also tumor cells of various kinds, fragments of 

 disintegrated thrombi, portions of heart valves, etc. Crystals of bili- 

 rubin have been found in the blood in icterus. 



Fat, in a moderate amount, is a normal ingredient of the blood during 

 digestion and in lactation. Under pathological conditions it may occur 

 in larger and smaller droplets. r f^sJip^mia occurs as^result of jleficient^ 

 oxidation in diabetes^in drunkards, and in some cases of dyspnoea from 

 various causes. The droplets are small and liable to escape observation. 



