230 THE MICROSCOPE. 



solution of Dr. J. J. Woodward, made as follows : 

 Best carmine, 15 grains ; borax, 1 drachm ; water, 5-- 

 ounces; alcohol (95 per cent.), 11 ounces: mix and 

 filter. Sections placed in this fluid will be stained 

 evenly, in a few seconds, of a violet-red colour. 

 Remove quickly and immerse them in a solution of 

 hydrochloric acid 1 part, alcohol 4 parts. Let them 

 remain until they assume a bright rose colour this 

 will be accomplished in a few seconds. Wash the 

 sections in distilled water and then transfer them to 

 alcohol and finish off in the usual way. Specimens 

 thus treated will have their nuclei and granules 

 stained, while the cell contents and fibrous tissue 

 remain uncoloured. 



The second solution is one composed of carmine and 

 indigo. The sections stained with the carmine solu- 

 tion must be immersed in a weak solution, 2 drops of 

 sulphin-digotate of soda in one ounce of a 95 per cent, 

 alcoholic solution, which should be filtered before using, 

 and there left from 6 to 18 hours, according to the 

 rapidity with which the elements take up the indigo. 

 When sufficiently stained, the sections are immersed in 

 strong alcohol ; they are then ready for mounting. The 

 sulphin-digotate of soda as prepared by Bullock makes 

 a solution of a deep greenish-blue colour, and the effect 

 of the paint upon the section is to leave the nuclei 

 bright red, while the fully- formed material of the cell 

 is slightly tinged blue. The connective tissue fibres 

 become stained deep blue, and the blood vessels are 

 purplish and mapped out with distinctness. Epithe- 

 lium cells and hair take the stain in a distinctive 

 manner, thus affording a means of differentiation in 

 epithelioma, the so-called pearls being brought out of a 

 different colour from the rest of the cells. 



Mr. J. W. Groves, 1 in an instructive paper on stained 

 sections of animal tissues, says the rule of almost uni- 

 versal application is that the fluid should be weak 

 and the quantity large in proportion to the number of 

 sections, or to the mass. ,A section placed in a solution 

 BO weak that 24 or 48 hours or more is required to give 



(1) Journal of the Quekett Microscopical Club, Nov., 1S79, p. 231. 



