172 BLOOD. 



with a watery solution of iodine, as they then assume a brown 

 colour. Blood-corpuscles which have escaped destruction may 

 also be made again visible in watered blood, since the solution of 

 iodine contracts the cell-wall, and gives it a yellow colour. The 

 more we add water to whipped blood, the darker it becomes in 

 reflected light, but at the same time it becomes translucent; while 

 the addition of salt renders the fluid turbid and again opaque, 

 and communicates a light red tint to it, a fact whose physical 

 explanation does not require notice in the present place. 



The following experiments refer solely to calves' blood. The 

 saline solutions were for the most part applied in the state of satu- 

 ration at + 15. 



In relation to the action of ether, Nasse remarks that it renders 

 the blood-cells smaller and paler, and he believes that a great part 

 of the pigment is extracted by it. The mere results of my experi- 

 ments on this subject are as follows : 



When 100 volumes of blood were shaken with 4' 8 volumes of 

 ether, no visible darkening of the blood could be detected ; the 

 ether did not again separate from the blood ; the blood-corpuscles 

 preserved their form. After 18 hours they slightly sank, but the 

 serum was not yellower than that of calves' blood in general ; many 

 corpuscles were then spherical, and some were distorted and had 

 partially lost their sharpness of outline. 



On shaking 100 volumes of blood with 8*1 volumes of ether, the 

 blood became decidedly darker ; the ether, however, in this case, 

 did not again separate ; most of the coloured cells disappeared, but 

 those which could still be detected were sharply outlined, spherical, 

 and faintly clouded on their surface ; the colourless cells were very 

 distinct. 



On mixing 100 volumes of blood with from 12*4 to 24'6 volumes 

 of ether, a dark brown red, transparent fluid was obtained ; here 

 also no ether appeared on the surface, but there was a separation 

 of a light yellowish sediment, which, when examined under the 

 microscope, presented the appearance of coagulated matter (shreds 

 of the membrane forming the cell-walls) ; only isolated coloured 

 corpuscles were seen, and they were pale and distended so as to 

 resemble fat-globules ; the colourless cells were as distinct as if the 

 blood had been treated with water. 



When equal volumes of blood and ether were mixed, the fluid 

 became very dark, but highly transparent; on standing, a great 

 part of the ether again separated from the blood ; here, also, there 

 was a deposition of yellowish flocculi ; under the microscope the 



