ACTION OF REAGENTS ON RED CORPUSCLES. 235 



change is associated with the death of the element, it cannot be 

 attributed to vital activity comparable with that which is seen in 

 the white cells. 



The disks show no signs of structure under the microscope ; 

 they look perfectly homogeneous transparent bodies of a pale 

 orange color, all efforts to demonstrate the limiting membranes, 

 formerly supposed to surround them, having failed. Their be- 

 havior when certain reagents are added to the blood shows that 

 the corpuscles have two constituents : (1) the coloring matter, 

 Oxyhcemoglobin ; and (2) the Stroma. The coloring matter may 

 be removed as above stated, by water from the corpuscles, and 

 then leaves a perfectly colorless transparent foundation or ground- 

 work, which appears to be in some way porous, so as to hold the 

 coloring matter in its interstices. The effect on the naked-eye 



FIG. 102. FIG. 103. 



fim&f - 



jfew^KP 



** O> ~ ^ "" t-'.-.-^Q.-':-: w !P?-"> 



fefessjrb"' 



FIG. 102. Red Corpuscles, shriveled by the addition of strong syrup, (w) White 

 Corpuscle. 

 FIG. 103. Blood Corpuscles after the addition of tannic acid. 



appearance of the blood produced by the removal of the coloring 

 matter from the stroma, is to alter the color and increase the 

 transparency of the fluid. The oxybsemoglobin now forms a 

 transparent, dark-red lalcey solution, and the corpuscles, being 

 quite colorless, are practically invisible. This transparency of 

 the fluid does not depend on any change in the oxyhsemoglobin, 

 but merely on its being dissolved out of the disks. This process, 

 which is commonly spoken of as rendering the blood " lakey," 

 may be brought about by the following means : (1) The addition of 

 about one-fourth its bulk of distilled water, to dissolve the coloring 

 matter out of the stroma, which may then be rendered obvious 

 by a weak solution of iodine. (2) By the addition of chloroform, 

 ether, neutral alkaline salts, or alkalies. (3) By passing repeated 



