BLOOD AND GLANDS 399 



precipitate on the filter, dries it, and dissolves it in 200 parts of 

 absolute methyl alcohol (the solution can be had ready made from 

 Griibler or Hollborn). (Or, simply mix 125 c.c. of 0-5 per cent, 

 solution of the eosin in methyl alcohol with 100 c.c. of 0-5 per 

 cent, solution of methylen blue). Cover-glass films are floated 

 on to this or smears are immersed and stained for four minutes. 

 Another method is to fix the film in the undiluted Jenner stain 

 for one minute, after which it is stained for three minutes in 

 stain to which two volumes of distilled water have been added. 

 Wash off the stain with distilled water until a faint pink colour 

 appears ; dry and examine. Erythrocytes red, all nuclei blue, 

 parasites blue, but with unstained nuclei. The May-Giemsa 

 stain is prepared in an almost similar manner, and is used in the 

 same way. 



Jenner 's Stain for Sections. The following method for sections, 

 proposed by Turnbull {Journ. of Path., 1931, p. 34), gives good 

 results in formol fixed material, and is widely used. Pieces are 

 fixed for as short a time as is compatible with complete fixation 

 in 4 per cent, neutral saline formaldehyde, or in the same buffered 

 to pH7 or to ^H5. Paraffin sections are rinsed in distilled water 

 and stained with one part of a stock solution of Jenner to one 

 part of distilled water for about forty-five minutes. They are 

 then differentiated with absolute alcohol, and mounted in Gurr's 

 neutral mounting medium. During differentiation they may be 

 cleared from time to time in xylol for examination. Stock solution 

 is made as follows : Pour 100 c.c. of analytical methyl alcohol 

 upon 0-3 grm. of Gurr's Jenner crystals, leave without shaking, 

 and decant after three hours. The stain should be stored in a 

 glass-stoppered bottle. Distilled water should be boiled and 

 cooled before use. 



AssMANN {Munch, med. Wochenschr., 1906, No. 28 ; Das eosin- 

 saure Methylenblau, Leipzig, 1908, p. 35) treats fresh films for 

 half a minute to three minutes in a Petrie dish with a few drops 

 of Jenner's solution (from Grtibler or Hollborn), then pours on 

 20 c.c. of distilled water with 5 drops of l/lO per cent, solution 

 of lithium carbonate, leaves for five minutes, rinses in distilled 

 water, dries with blotting paper, and mounts in neutral balsam. 



The foregoing mixtures give a stain — seemingly due to the 

 formation of an eosinate of methylen blue — in which the nuclei 

 of blood cells are blue and their plasma red to violet. It was 

 made out by Romanowsky {St. Petersburger med. Wochenschr., 

 1891) that under certain conditions mixtures of these two dyes 

 give a stain which is in some respects the inverse of this, blood 

 cells being stained in divers hues, according to their kinds, and 

 any protozoon -parasites that may be present showing red nuclei 

 and blue jDlasma, which greatly facilitates their detection and 

 diagnosis. This reaction appears to be due to the formation of 



