196 KEVIEW— TROPICAL MEDICINE, ETC. 



Sprue— in urine which indicates active degenerative changes in the pancreas (for details, see British 



cmiinued Medical Journal, May 19th, 1906), and which may be employed to differentiate these cases 

 from sprue. 



Staining. There is no end to the production of new staining methods, and a large 

 volume might be written on this subject alone, even if stains for blood only were considered. 

 A few odd notes may, however, be useful. 



One often has blood films sent in, which, owing to their age and their long exposure to 

 heat, cannot be got to stain well by any of the Romanowsky methods. The red blood 

 corpuscles do not take on the proper eosin hue, but appear green or greenish-blue, while the 

 leucocytes at the same time often stain faintly. One had much trouble with these old films 

 until Dr. Daniels, of Loudon, kindly gave one the following method :— 



Treat the slide before staining (and this is the special point) with a mixture of absolute 

 alcohol one ounce and three to five drops of glacial acid for a few minutes. "Wash in distilled 

 water, then stain in the usual manner. Occasionally this procedure fails, but as a rule it 

 succeeds admirably, and has proved of great service. 



The best staining methods for the amoeba of dysentery are not, as a rule, well described 

 in English text-books, therefore a paper by Harti on this subject may be quoted : — 



Film preparations to demonstrate Amceba coli are, as a rule, generally found not to give satisfactory results. 

 This is no doubt due to the comparatively large size and delicate structure of the organism. 



By mixing in a test-tube a large volume of the infected material (either pus from a hepatic abscess or mucus 

 from dysenteric stools) with a dilute logwood stain, and collecting the resulting dyed matter in glycerin, quite 

 good results may be obtained. 



The following are details of the method : — 



Staining Solution 

 Hsematein, 3 grains 



Potassium alum, 1 grain 



Acetic acid, B.P. (33 per cent.), 1 minim 



Alcohol, 80 minims 



Distilled water, to 1 fluid ounce 



To be used diluted with about four times its volume of distilled water. 



1. Pill a test-tube to two-thirds of its capacity with the diluted logwood stain ; add the infected material to 

 the extent of about half-an-inch and diffuse by shaking gently for a few minutes. Any coarse particles are 

 removed by straining through gauze and rejected. After straining for three hours the stained cells will be 

 found to have settled to the bottom and the supernatant fluid can be poured off. 



2. The colour of the stained structures is now to be developed by nearly filling up the tube with tap- 

 water or a weak solution of lithium carbonate (half a grain to the ounce). Glycerin, suflBcient to form a 

 layer of, say, three-quarters of an inch at the bottom, is then carefully added to the tube. It is now set aside 

 to allow the stained material to settle down into the glycerin. Deposition will have taken place in sLx or 

 seven hours. 



3. The supernatant fluid is poured off and the stained material in the glycerin transferred to slides and 

 cover-glasses cemented on. 



When the amcebfe are to be mounted in Canada balsam the procedure is somewhat different and not quite 

 so simple. Glycerin must of course be omitted. 



The water having been poured off from the stained material, dilute .alcohol is added and the tube is set aside 

 for an hour or two. " The deposit is then collected on a filter paper and drained. 



The filter paper with its contents is then folded up to form a packet, tied with a thread, and suspended in 

 absolute alcohol to dehydrate. When dehydration is considered complete, transfer the packet to some clearing 

 agent and again to a fresh supply of the clearing agent. (Eectified coal-tar naphtha answers the purpose 

 admirably and is inexpensive.) 



The cleared preparation, after draining, can then be mounted in Canada balsam in the usual way. 



Another method is that used by Dr. Wenyon, and which, though a little tedious, 

 produces excellent results. It is here given as shortly as possible : — 



Fixing ^«ic^= Saturated sublimate, 2 parts. 

 Alcohol absolute, 1 part. 



Fffices spread out by needle on cover-slips. Without drying, drop slip, film-side down, on 

 the fixing fluid, best warmed to about 60° C. After a few minutes, reverse film and allow to 

 sink. Fix for twenty to thirty minutes. Wash in distilled water for five minutes, and then 

 place in 70 per cent, alcohol to which a few drops of Gram's Iodine has been added. Leave 

 in this at least two hours (for a day if one likes). Transfer to distilled water and stain with 

 Heidenhain's Iron Haematoxylin, Delafield's Haematoxylin or Borax Carmine. 



' Hart, T. (December 15th, 1903), "The Preparation of Permanent Stained Specimens of Amoeba Coli." 

 Journal nf Tropical Mrdicine and Hygiene, Vol. VI. 



