470 
APPENDIX I 
METHOD OF PREPARING AND STAINING WET FILMS, USED 
DURING THE FOREGOING INVESTIGATIONS 
Place a very thin layer of albumen-glycerine on a clean slide 
The best method is perhaps to put a drop the size of a large pin’s head 
on the slide, and to spread this with a clean duster over the slide. 
On top of this layer spread a drop of blood in the usual way, and dip 
the slide, while wet, into the fixing solution (Flemming’s strong 
solution was usually used). Leave it for about five to ten minutes, 
wash immediately in water, and pass the slide through alcohols in 
consecutive order, increasing by io per cent, at a time to absolute 
alcohol. Then back from absolute into 80 per cent, alcohol in which 
is contained iodine and potassium iodide. In order to prepare the 
solution of 80 per cent, alcohol containing iodine and potassium iodide, 
make up a concentrated solution of potassium iodide in water, and 
iodine in alcohol, mix them together, and add them to some So per 
cent, alcohol until the mixture becomes a dark brown colour. Leave 
the slide in this from five to ten minutes, and then bring it int0 
30 per cent, alcohol. Use for staining either aniline safranine faach 
isabes), or the following solution :-Prepare a concentrated watery 
so ution of safranine (Griibler) and a concentrated alcoholic solution 
o sa ranin, mix them in equal parts, and then add pure aniline oil 
sixmonfT ‘i? 6 l ° tlme ' and ieaVe tHe S ° Iuti0n t0 ri P“ thfeC “ 
Wash nff 5 ' “ tHiS SOluti ™ fOT f ™> an hour to two hours. 
“ 5afranin ' and stain afterwards with polych«»” c 
(*£££“ Ne ,. 6 ™" e methylene blue purissimum 
S 1 tL,“cT; d water and 5 e— ^ boaate ' 
the stamin, ™ , t0 n npen: the ° lder the solution the be#* 
differentiate with o ° ff ^ methylene blu& !l 
comes out Brin? th T tannm > as long as the blue s a 
Bnng the S h de up through ^ __ into 
the 
absolute alcohol Tl r P trough alcohols, as above, 
slide into aniline oTl Z ^ ^ a reddlsh Now dip 
tinge; the aniline oil takes 1 1 ’ 1 f ddlS ^ C ° lour chan S es to a purpl^” 
stain left by the on ' °. U &t * le same time the excess of b 
Balsam under a coverstp ^ ^ Mount in 
