308 APPENDIX 



the dilute solution is only required for staining at the moment, 

 and not for diluting the fluid in the bottles, a 1 p.c. solution of 

 alum or distilled water may be used. 



Comparison of the hcematoxylin fluids. Delafield's hsema- 

 toxylin gives perhaps the best preparations for the student, 

 but it is apt to overstain and it requires frequent filtering ; 

 these disadvantages are much less marked in the case of acid- 

 hsematoxylin ; the latter if used should be diluted so as to stain 

 in 15 to 30 minutes (see also p. 63). 



Iron-hsematoxylin (Heidenhain), cp. p. 287. The chief use 

 of the method is for staining the centrosome ; it stains also 

 for the chromatin of nuclei, striated muscle (cp. p. 100), the 

 granules of the pancreas and of various other cells. 

 Alum carmine. 



Carmine 1 gram 



2*5 p.c. ammonia alum 100 c.c. 

 Boil for 15 minutes. Let cool and filter. 

 Carmalum (Mayer). 



Carminic acid 1 grm. 

 Alum 10 grm. 



Water 200 c.c. 



Warm and filter. 



Picrocarmine (Bourne). Add 5 c.c. of ammonia to 2 grams 

 carmine in a bottle capable of containing about 250 c.c. Stopper, 

 shake and put aside till next day. Add slowly, shaking the 

 while, 200 c.c. of a saturated solution of picric acid in distilled 

 water. Put aside till next day. Add slowly, constantly stirring, 

 11 c.c. of 5 p.c. acetic acid. Put aside till next day. Filter; 

 to the filtrate add four drops of ammonia, put back in the 

 stoppered bottle. 



Picrocarmine (Ranvier). To a saturated solution of picric 

 acid add a saturated ammoniacal solution of carmine till a 

 precipitate occurs. Evaporate in a water bath till the volume 

 is reduced by four-fifths. Filter, and evaporate the filtrate to 

 dryness. A crystalline mass is thus obtained. Make a 1 p.c. 

 solution in distilled water, diluting before use as required. 



