CLASSIFICATION OF ANGIOSPERMS. 



321 



and is closely associated with other resinous substances. Japanese 

 lac is thinned with camphor, or mixed with linseed oil and on 

 drying in a moist atmosphere forms the most indestructible 

 varnish known. Various pigments are used, as vermillion, gam- 

 boge, acetate of iron and other substances. The best glossy 

 black colors are obtained by the addition of iron. 



Rhus glabra or the Scarlet Sumac is a smooth shrub. 

 The leaves are 11- to 31 -foliate, the leaflets being lanceolate, acu- 



"mm 





Fin. 164. Gallic acid: long orthorhombic crystals obtained from an aqueous solution. 



minate, sharply serrate, dark green above and tomentose below ; 

 the flowers are greenish, polygamous and in terminal panicles ; 

 the fruit is official (p. 569). 



Chinese galls are excrescences produced on Rhus semialata 

 as a result of the stings of an Aphis. Japanese galls are similar 

 formations occurring on Rhus japonica. (See Galla.) 



Pistacia Lentiscus is a shrub or tree, which is found growing 

 in the Grecian Archipelago. The leaves are pinnately compound 

 and with winged axis, the leaflets being alternate, oblong, entire. 



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