128 NORTH AMERICAN INSECTS. 



is extensively used in dyeing. Mixed with very fine 

 sand, it forms grindstones, and added to lamp or 

 ivory black, being first dissolved in water and a 

 little borax, it composes an ink of a very good 

 quality, and when dried not easily acted upon by 

 dampness or moisture. Notwithstanding the vast 

 amount of this substance that is constantly consumed 

 in manufactures of various kinds throughout the 

 world, still this little Insect produces it so fast and 

 so abundantly, that were the consumption of shell- 

 lac ten times greater than it is, it could readily be 

 supplied. 



There are many other, species of Shield-lice found 

 in the old countries, which have from time immemorial 

 furnished a substance used for dyeing red, and which 

 are still used for that purpose. Hence their name 

 among the Greeks and Romans was " Coccus," by 

 the Arabs called " Kermes," and by the Persians 

 " Alkermes." 



Professor Ehrenberg, of Berlin, to whom the 

 science is so much indebted for his laborious micro- 

 scopic investigations of the Animalcules, found large 

 Tamarix-trees (Tamarix mannifera, Ehrenb.) upon 

 Mount Sinai, the young shoots of which were covered 

 with a species of Shield-louse, which he called Coccus 

 Matmiferus. 



