ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 349 



at least strongly suspecting, the presence or absence of typhoid in a 

 non-inocnlated person. 



With a coloured grease glass pencil, or a piece of wax, draw a line 

 across the middle of two slides at right angles to their long axes. 

 Spread a film of the blood to be examined on one half of each slide, 

 and, when dry, spread a film of one's own blood, or that of a person 

 who has not had typhoid or who has not been protectively inoculated 

 against it, as a control, on the other half of each slide. The film may 

 be as thin as that ordinarily used for stained films, or a little thicker. 

 Dry. By means of a platinum loop or pipette place a small drop of an 

 emulsion of killed typhoid bacilli on the centre of each half of both 

 slides, and with the platinum loop, rub the drop well over the film of 

 blood, taking care not to pass from one half of the film to the other 

 without sterilizing the needle. On one slide carefully place a cover- 

 glass on each half, taking care that the two cover-glasses are well 

 separated in the middle by the mark of the grease pencil. Place the 

 other slide in a piece of wet blotting-paper, and cover with a Petri 

 dish to prevent evaporation, for a period of fifteen to twenty minutes. 

 At the end of that time dry carefully over the flame, and then stain. 



Examine both halves of the first slide under the Microscope. After 

 fifteen minutes clumps of agglutinated bacilli will be seen, if the blood 

 be from a typhoid case or from an inoculated person, while on the 

 control half of the slide the bacilli will show no sign of clumping. The 

 film, stained with Leishmann or Giemsa, will show on one half patches 

 of agglutinated bacilli, while on the control half the bacilli will be 

 more or less evenly distributed. Paratyphoid A and B fever can be 

 diagnosed by a similar proceeding, employing cultures of these 

 organisms, instead of the typhoid bacillus. 



Jun& 21st, 1916 2 B 



