MOIST CHAMBER. 41 



13 6'), and the glass tube is connected by India-rubber 

 tubing to a bottle containing a few drops of chloro- 

 form and furnished with a second tube, through 

 which air can be blown. 



Fig. 



Chamber for passing a gas or vapor over a preparation under the 

 microscope. 



Before the cover-glass is superposed the blood 

 should first have been spread out upon it into a thin 

 layer, so that the chloroform vapor may readily act 

 upon all parts. 



Everything being thus prepared, and some of the 

 blood corpuscles having bean brought clearly under 

 observation, air is blown gently into the bottle, and 

 passing through it becomes charged with the vapor 

 of chloroform, which is conveyed by the tube into 

 the moist chamber, where it acts upon the layer of 

 blood which is on the under surface of the cover- 

 glass. After a short time it will be seen that the 

 red corpuscles, as under the action of water and 

 dilute acids, at first become globular, and subse- 

 quently their haemoglobin becomes dissolved and 

 discharged out in the serum. It will further be ob- 

 served, both in this and in the other preparations in 

 which this change has taken place in the red cor- 

 puscles, that to the naked eye the blood has changed 

 from scarlet to lake, and that whereas when the cor- 

 puscles were intact even a thin layer of blood pre- 

 sented a somewhat opaque appearance, it is now 



4* 



