EXAMINATION FOR MALARIA 651 



stained at once, and they will keep indefinitely in a dry place. 

 The method of packing stained or unstained films face to face or 

 wrapped in paper is a barbarous one ; the surfaces soon get 

 scratched and dirty. The best plan is to pack them back to 

 back in a racked box, or if this is not at hand, stick a small piece 

 of gummed paper at the end of the slide on the film side, and 

 when this is thoroughly dry, but not before, they can be packed 

 together. 



It is essential that the films should be absolutely dry before they 

 are mounted, and if they are mounted in Canada balsam or cedar- 

 oil they will sooner or later fade and be perfectly useless. The 

 best plan is to mount them in paroleiii or liquid paraffin as 

 described by Coles (Lancet, April 1, 1911), which has also been 

 advocated by G-iemsa. 



If the above-named stains are not available staining may also 

 be done in a half-saturated aqueous solution of inethylene-blue 

 or in Loffler's blue for half an hour, washing in water, and counter- 

 staining with a very weak eosin solution for a few seconds, washing 

 and drying. Manson recommends treating the films with a very 

 weak acetic acid two or three drops to the ounce of water to 

 dissolve out the haemoglobin, and, after washing, staining in the 

 following solution for half a minute : 



Borax ....... 5 parts 



Methylene-blue . . . . .0-5 part 



Water 100 parts 



washing, drying, and mounting in xylol balsam. 



Hsematoxylin (Ehrlich's, or Mayer's heemalum) is preferable 

 for permanent preparations, and in hot countries, where methy- 

 lene-blue rapidly fades. The preparations may be counter- 

 stained with a weak solution of eosin. 



Ross recommends for rapid diagnosis the use of thick blood films, 

 from which the haemoglobin is first removed with very dilute 

 acetic acid ; the films are then stained with Leishman's stain, 

 and examined with a -in. objective. Practice is required for 

 this method. 



In Order to demonstrate the flagellated organisms Manson 

 recommends the following procedure : Thirty or forty strips of 

 thick blotting-paper (3 in. by 1| in.), each having an oblong hole 

 (f in. by in.) cut lengthways in the centre, are prepared, moist- 

 ened with water, and laid on a sheet of window glass. A patient 



