AND HOW TO USE IT. 239 



glycerine, thus tempered with a little muriatic acid (i to 2 per 

 cent.) to the microscopic preparations, the cell-body is seen to 

 gradually lose its colour, and the carmine only is retained by 

 the nucleus. For mounting in glycerine, the preparation is to 

 be washed with water containing acetic acid (Schweigger Seidel). 



Haematoxylin (Boehmer's). — This is much preferred to the 

 carmine, and there are a great many modifications. Dissolve 

 20 grains of hematoxylin in half an ounce of absolute alcohol ; 

 then dissolve 2 grains of alum in i ounce of distilled water. 

 Some drops of the first solution are added to the second, which, 

 after a short time, becomes a beautiful violet. It improves after 

 keeping for a few days, and should always be filtered before using. 

 (Thin.) 



Kleinenberg's Solution (Foster and Balfour). — 

 (i) Make a saturated solution of crystallised calcium chloride 

 in 70 per cent, of alcohol, and add alum to saturation. 



(2) Make also a saturated solution of alum in 70 per cent, of 

 alcohol. Add one part of No. i to eight parts of No. 2, and to 

 the mixture add a few drops of a saturated solution of haema- 

 toxylin in absolute alcohol. The stained sections are placed at 

 once in strong spirit. 



Aqueous Logwood Stain. — Take 60 grms. of dried extract 

 of hsematoxyhn, 180 grms. of powdered alum, and rub them tho- 

 roughly together in a mortar, adding slowly 300 cc. of distilled 

 water ; mix carefully, and afterwards filter. To the filtrate add 

 20 cc. of absolute alcohol and preserve in a stoppered bottle. 

 This solution should be kept in a cool place for at least a fort- 

 night before using. The older it is, the more excellent it becomes. 

 (Harris and Power.) 



Mitchell's Hematin Staining Fluid.*— This is one of the best 

 logwood stains, and we believe it will take the place of nearly all 

 the older stains. Make as follows : — Finely ground logwood, 

 2 oz. ; sulph. aluminium and potash alum, 9 drms. ; glycerine, 

 4 fluid ounces ; distilled water, a sufficient quantity. Moisten the 

 ground logwood with sufficient cold water to damp it, place in a 



* Academy of Natural Science, Philadelphia. 



