268 THE AMERICAN MONTHLY [December, 



The noteworthy features, then, of these carmine stains for nervous 

 tissues are the surpassing beauty and clearness with which the nerve 

 cells — especially their processes — and axis-cylinders are shown, in ad- 

 dition to which the neuroglia cells and fibres are often deeply colored. 

 The merits of these stains are illustrated nowhere more strikingly than 

 in sections of successfully prepared cerebellum, in which the cells of 

 Purkinje with their splendid branched processes form a picture in 

 telling contrast with the exhibition of these elements as usually seen in 

 carmine or haematoxylin preparations. The cells of the cerebral cor- 

 tex foi'm another instance of the value of the method, the long delicate 

 processes being traceable to their finest ramifications as deeply stained 

 red lines on a colorless ground. 



While sections of spinal cord so stained are very beautiful, the excel- 

 lence of the results obtainable by alum-haematoxylin and other dyes 

 . enders the preparations by the method described less conspicuous ; the 

 white matter in such specimens, however, is often especially well 

 shown. The nuclei of the neuroglia cells in the cords of young sub- 

 jects are especially prominent. The value of the sodium carminate 

 stain in demonstrating the areas of degeneration has been established. 



Another, and by no means unimportant, merit of these stains lies in 

 their especial adaptation to photography ; employed in connection with 

 the green glass ray-filter described in a former number of this journal*, 

 they possess that degree of actinic contrast most favorable to secure 

 crisp and vigorous negatives. What the Weigert's stain accomplishes 

 for the medullated nerve fibres these carmine stainings do for the pro- 

 cesses of the nerve cells and axis-cylinders ; the advantages of a ready 

 process of double staining uniting the merits of both are evident. The 

 recently published acid-hasmatoxylin method of Kultschitzkyf appar- 

 ently offers the means of securing such double stains, but so far my at- 

 tempts to unite the two, while producing beautiful pictures, have failed 

 to furnish pi - eparations in which the features of the Weigert method 

 were sufficiently pronounced ; however, subsequent experiments mav 

 prove more satisfactory. 



University of Pennsylvania, Sept. 2, 1889. 



Cuccati's Soluble Carmine. — Dr. Grovarini Cuccati describes, in 

 the Zeitschrift fur Wissenschaftliche Mikroskofiie, a carmine solu- 

 tion which he uses in connection with a cold saturated solution of ammo- 

 nium picrate in staining microscopical preparations. The carmine solu- 

 tion is prepared by dissolving 20 grains of sodium carbonate in ioo cubic 

 centimetres of water, adding thereto 5 grains of Griibler's pulverized 

 carmine, mixing well, and bringing to a boil. When ebullition has been 

 effected the capule is removed from the fire and 30 grams of absolute 

 alcohol added. After cooling, the solution is filtered and immediately 

 mixed with 300 grains of water previously acidulated with S cubic cen- 

 timetres of acetic acid, and, finally, 2 grains of chloral hydrate are 

 added and dissolved in the mixture. The ammonium picrate solution 

 is made by first moistening picric acid with sufficient ammonia to 

 make a thin paste, and adding sufficient cold distilled water to nearly, 

 but not quite, dissolve the mixture. In staining, equal parts of the two 

 solutions are used. — National Druggist. 



*Vol. VII, July, 1886. 



fKultschitzky : Ueber eine neue Methode der Haematoxylin Fiirbung ; Anatomisch, Anzeiger, Bd. 

 IV, No. 7, 1889. 



