64 UTILIZATION OF MINUTE LIFE. 



yellow powder, which stains the clothes. A tree 

 common enough in India, and which is called Ter- 

 minalia citrina, yields a sort of gall, which serves in 

 that country as a dye j to it indeed the natives owe 

 their best and most durable yellow colour. It is 

 produced by a hitherto unknown insect. Among 

 the little " money- spiders " (Trombidium) which 

 attract the attention of children in the garden about 

 spring, Trombidium tinctorium is used in Guinea 

 and Surinam as a dye. I have observed that when 

 acid vegetable colours of a yellow tint can be 

 fixed upon silk, cotton, wool, etc., they can almost 

 always be turned crimson by alkalies. It is im- 

 possible yet to say what influence the newly dis- 

 covered colour magenta will have upon the cochi- 

 neal production. But as carminium and magenta 

 are so very different in properties, it is probable 

 that the production of magenta dye will not mate- 

 rially affect that of cochineal. 



