144 CARMINE AND COCHINEAL STAINS. 



It' has over the new fluid (next ) the advantage of being more 

 highly alcoholic ; and it does not contain free acid, so that it can 

 be used with calcareous structures which it is wished to preserve 

 which the new fluid cannot. For specimens of Pluteus, for instance, 

 I find it excellent. But it only gives good results with such objects 

 as contain the necessary salts, 212. 



236. MAYER'S Alcoholic Cochineal, New Formula (Mitth. Zool. Stat. 

 Neapel, x, 1892, p. 498). Cochineal, 5 grms. ; chloride of calcium, 

 5 grms. ; chloride of aluminium, 0-5 grm. ; nitric acid of 1-20 sp. gr., 

 8 drops ; 50 per cent, alcohol, 100 c.c. Powder the cochineal and rub 

 up with the salts, add the alcohol and acid, heat to boiling-point, leave 

 to cool, leave for some days standing with frequent agitation, filter. 



Use as the old tincture, the objects being prepared and washed out 

 with 50 per cent, alcohol. Mayer only recommends it as a succedaneum 

 of paracarmine. 



Since this fluid contains in itself all the necessary salts ( 212), it gives 

 good results with all classes of objects. 



