636 APPENDIX. 
cases, and in cases.of mixed malarial infection occur- 
ring in malarial regions, a careful blood examination 
enables a positive diagnosis to be made in a large 
majority. 
Technique of Blood Examinations for Malaria. The 
finding of the parasite should not prevent us from 
seeking further in doubtful cases by means of the 
Widal reaction and blood cultures for other infections 
which may exist along with the malaria. 
The parasites require a proper technique and a 
certain experience for their recognition. The fresh 
blood, when it can be obtained, should be examined, 
but if no bodies be found, stained preparations should 
always be later searched through; the drops may be 
taken either from the tip of the finger or from the 
lobe of the ear. It is important to have a perfectly 
clean cover-glass and slide, and to cleanse the skin 
thoroughly and to wipe it dry, so as to avoid dirt and 
perspiration. A very small drop should be taken, and 
care must be exercised that the cover-slips, when pressed 
against the blood-drop, do not touch the skin. The 
drop should be so small that the corpuscles are spread 
out in a uniform layer and are not in rolls when the 
cover-glass is laid upon the slide, for the intracorpus- 
cular form cannot be well seen unless the blood-disk 
presents the flattened surface. For making permanent 
preparations the blood is collected upon cover-glasses 
in very thin films, which should be instantly dried. 
The blood-cells are fixed by immersion in equal parts 
of alcohol (95 per cent.) and ether for fifteen minutes, 
or by exposing for five minutes over a wide-mouthed 
bottle containing 25 per cent. solution of formalin, or 
by heating to 120° C. for ten minutes. Ewing advises 
