Journal of Applied Microscopy. 299 



tilled water. Allow the mixture to cool and settle ; filter ; add a crystal of 

 thymol to preserve from mould. The stain is ready for use as soon as made, 

 and it keeps well. 



HaidenhaM s Iron Alum HcE7natoxyliti. — Two solutions are used, and they 

 are never to be mixed. 



(a). A Xy^ to 4 per cent, aqueous solution of ammonia sulphate of iron. 

 (h). A Y-i per cent, aqueous solution of haematoxylin. 



Cyanin, Eryt/irosin, Safrani?i, Gentian Violet. — Numerous formulae are 

 given foi" these and other anilin stains, but the following general formula gives 

 excellent results : 



Make a 3 per cent, solution of anilin oil in distilled water ; shake thoroughly 

 and frequently for a day ; add enough alcohol to make the whole mixture about 

 20 per cent, alcohol. Add 1 g. of cyanin or erythrosin, etc., as the case may be, 

 to 100 cc. of the solution. Safranin is often used in strong alcoholic solution, 

 and even with the above formula it is better to dissolve the safranin in strong 

 alcohol before adding it to the mixture. 



Acid Fuchsin. — Use a 1 or 2 per cent, solution in water, or 70 per cent, 

 alcohol. 



Iodine Green. — Use a 1 to 4 per cent, solution in water or alcohol. A 3 

 per cent, solution in 70 per cent, alcohol is very good for the vascular system of 

 plants. 



Mixtures of Fuchsin and Iodine Green. — The following formula is often used 

 for karyokinetic figures : 



(a). A yy per cent, solution of fuchsin in water. 

 (h). A y2 per cent, solution of iodine green in water. 



Just before using mix a and b in various proportions until you find what is 

 needed for the particular case. 



Orange G. — Use a saturated aqueous solution. 



Eosin — A 1 to 5 per cent, solution in water or alcohol. A 2 per cent, 

 aqueous solution is good for material to be mounted in glycerine, but a 2 per 

 cent, solution in 7" per cent, alcohol is better for balsam mounts. The stronger 

 solution may be diluted as needed for special cases. 



FoRMUL.t FOR Alcohols. — The grades of alcohol in most common use are 

 35 per cent., 50 per cent., 70 per cent., i^S per cent., 95 per cent., and 100 per 

 cent. The 100 per cent, is expensive, and great care should be taken to keep 

 the bottle well corked or the stender dish closely covered. The following 

 formulae will enable any one to make the other grades of alcohol from 95 per 

 cent, alcohol and water : 



95 35 95 5i3 95 70 95 85 



GO 



45 



25 



10 



The above are the formulae for 35 per cent., 50 per cent., 70 per cent., and 

 85 per cent, alcohol. Any other grade can be gotten^in the same way. In the 

 first formula, substract 35 from 95 ; the result, 60, is the number of cubic 



