5 2 MICRO-CHEMICAL REAGENTS. 



dipped into the water, remaining from twenty sec- 

 onds to a minute in the carmine, being well rinsed 

 in the first watch-glass of alcohol, and staying ten 

 to twenty minutes in each of the others. It is 

 left in the oil of cloves until cleared up, when 

 it is ready for mounting in balsam. The gen- 

 eral experience of teachers seems to be, how- 

 ever, that more time is consumed in making the 

 few successful preparations than they are worth. 

 W. T.] 



Beale's carmine, which is especially useful in dif- 

 ferentiating the nucleus, is prepared by dissolving 

 .6 gm. carmine in 2 gm. boiling ammonia water. 

 The solution is set aside for an hour to allow 

 some of the ammonia to escape. Sixty gm. dis- 

 tilled water, 60 gm. glycerine, and 15 gm. absolute 

 alcohol are then added. After standing for some 

 time, the fluid is filtered and ready for use. 1 



Strasburger, in the study of the embryo sac, 

 stains the protoplasm with a boracic solution of 

 carmine, prepared as follows : Four parts borax 

 are dissolved in fifty-six parts distilled water. To 

 this one part of carmine is added. One volume 

 of this solution is diluted with two volumes abso- 

 lute alcohol and filtered. By the use of this dye 

 the study of the forms of the nucleus is greatly 

 facilitated. The preparations may be preserved 

 in glycerine or glycerine jelly. 2 



1 Frey : Mikroskop, p. 90. 



2 Strasburger: Zellbild. u. Zelltheilg., 1880, p. 9. 



