l94 THE MICROSCOPE 



saturate solution of acetate of potash, 1 2 drops ; grape sugar, 

 16 grains; freshly distilled water, i ounce (Dr. Maddox). The 

 whole is to be boiled in a large test-tube or beaker for fifteen 

 minutes, and covered, whilst boiling and cooHng ; when settled, 

 it should be poured into perfectly clean 2-drachm stoppered 

 bottles and kept for use. In using Maddox's growing slide, the 

 fungi or spores are placed, with a droplet of the fluid required, on 

 a glass cover large enough to cover the tinfoil cell. This, after 

 examination to see that no extraneous matter is introduced, is 

 placed over the tinfoil, and the edges fastened with wax softened 

 in oil, leaving free spaces for entrance of air. CoJm^s fluid is also 

 good for protophytic fungi (Schizomycetes, consisting of Bacteria, 

 Vibriones, etc.). The solution is composed of i part of potassium 

 phosphate, i part of magnesium sulphate, 2 parts of ammonium 

 tartrate, and o'l part of calcium chloride; dissolved in 200 parts 

 of distilled water. 



Carmine Fluid (Beale). See page 186. Staining vegetable 

 tissues and germinal matter : — carmine, 10 grains ; strong liquor 

 ammoniae, J drachm ; Price's glycerine, 2 ounces ; distilled water, 

 2 ounces ; alcohol, 4 drachms. Put the carmine in small 

 fragments in a test-tube and add the ammonia. By agitation, and 

 the heat of a spirit-lamp, the carmine is soon dissolved. The 

 ammoniacal solution is to be boiled for a fewseconds, then allowed 

 to cool. After the lapse of an hour, much of the excess of ammonia 

 will have escaped. The glycerine, water, and alcohol may then 

 be added, the whole passed through a filter or allowed to stand 

 for some time, and the perfectly clear supernatant fluid poured 

 off and kept for use. This solution will keep for months, but 

 sometimes a little carmine is deposited, owing to the escape of 

 ammonia, in which case one or two drops of liquor ammonias 

 may be added to the four ounces of carmine solution. 



Solution of Osmic Acid.— Osmic acid, i part ; distilled water, 

 100 parts ; is the strength generally used for staining, although, 

 of course, circumstances will alter this. Fat-cells and oil-globules 

 are coloured by it. 



Schultze's Test.— Wash the substance which is to be examined 

 in water, pour off the water, and then moisten it with a drop of 



