58 UTILIZATION OF MINUTE LIFE. 



time ago the author of this work thought he had 

 discovered carminium in the bark of the alder tree, 

 but it turned out to be another colouring matter, 

 still more interesting in a chemical point of view. 



The colouring matter of the cochineal, like that 

 of madder, or Turkey-red, becomes yellow by the 

 action of acids, but we can distinguish it from the 

 latter, for when carminium is separated from the 

 acid, it appears with its usual red colour, whilst 

 madder remains yellow. 



Light has a peculiar action upon carmine the 

 beautiful crimson lake obtained by precipitating an 

 alkaline solution of cochineal by alum. Mr. Hunt 

 has shown that when this lake is prepared in the 

 dark, it is of far less brilliant a colour than when 

 prepared in the sunshine. The same fact has been 

 observed for other colours, such as Prussian 

 blue, etc. 



The colouring matter for the face called rouge, 

 employed upon the stage and sometimes off it is 

 made by mixing half a pound of prepared chalk with 

 two ounces of freshly prepared carmine. This is the 

 only red colouring matter that should be tolerated 

 for this purpose, as it is perfectly harmless; the 

 other products sometimes sold as such are extremely 

 hurtful, from their venomous properties. M. Cheva- 

 lier of Paris has very recently made a long report 

 upon the sufferings produced among actors and 



