384 PLANTS AND MAN 



The HARD RESINS are generally solid, translucent, brittle sub- 

 stances lacking taste or odor, and containing little or no essential 

 oil. Because of the latter fact, and the ease with which they dis- 

 solve in alcohol, the hard resin group contains those most impor- 

 tant commercially, namely, the copals and damars. Copals are 

 the hardest of the varnish resins, containing practically no essen- 

 tial oil and yielding a hard, elastic finish which is desirable for 

 outdoor work. There are a number of copals, which come from 

 widely scattered geographic areas and widely different tree 

 species. Zanzibar copal comes from the East African coast, where 

 it is sometimes collected from trunks and branches of living trees, 

 but more often from fossil tree deposits. The West African copals 

 are likewise mainly of fossil origin, although living trees yield 

 small amounts of the commercial supply. Kauri copal is obtained 

 from the kauri pine of New Zealand, which is the largest tree of 

 its region. Most of this resin is dug from the ground, especially 

 in swampy areas, although an inferior grade of resin is obtained 

 by tapping the live pines. Other copals, somewhat softer in 

 nature and used for interior work, come from East Indian, 

 Malayan, Philippine, and South American tree sources. 



Damars are softer resins than are the copals, and are used 

 mostly in the manufacture of nitrocellulose lacquers and spirit 

 varnishes. They are lighter in color and adhere better than the 

 copal resins. Unlike the copals, which come from coniferous 

 trees, the damars have their origin in Angiosperm trees of 

 southeastern Asiaj notably several species abundant in Sumatra 

 and Malaya^ 



Amber is a fossil resin from an extinct pine which once 

 flourished in the vicinity of the Baltic Sea. This resin is the hard- 

 est known, yielding a very fine varnish which is too expensive for 

 common use. Its chief use today is for the manufacture of ciga- 

 rette and cigar holders, and mouthpieces for pipes. Often found 

 imbedded in these fossil amber deposits are insects, which lived in 

 previous geological eras and were captured by the flow of fresh 

 resin on the tree trunk, to be preserved for scientific scrutiny 

 some millions of years later. 



Lacquer is a natural varnish that is obtained principally 

 as an exudate of the lacquer tree — related to our sumac — ^which 



