194 THE USES OF PLANTS. 



SHOLA-PITH, derived from the Indian dUsckyomene 

 aspera, L., for hats, and that of the fibro-vascular 

 skeleton of the gourd Luffa cegyptiaca, DC, as a bath- 

 towel, are among the more anomalous products. The 

 various INSECT-POWDERS derived from the powdered 

 flowers of Pyrethmm, the use of Quillaia bark as a 

 hair-wash, and of BAY-RUM for the same purpose, 

 could not strictly be classed under Materia Medica ; 

 nor could those extensive industries, the manufacture 

 of acids, such as acetic and oxalic acids from saw- 

 dust ; pyrogallic, gallic, and tannic acids from galls; or 

 valerianic acid from potato-spirit. 



The long-practised use of the heads of the TEAZLE 

 (Dipsacus fullonum^ L.) to raise a pile on cloth is in- 

 teresting as a case in which art has failed to supersede 

 a natural product. The cultivated form, with a cylin- 

 drical head, may be derived from the wild species in 

 which the head is ovate. The flower-head is covered 

 with recurved, elastic, hooked scales. Rows of these 

 heads in a frame form part of the gig-mill, or dress- 

 ing-machine, metallic teazles not having proved satis- 

 factory. 



The importation of the VEGETABLE IVORY, or 

 COROZO-NUT (Phytelephas macrocarpa, Hook.), and 

 the COQUILLA-NUT (Attalea funifera, Mart.) for 

 buttons, umbrella - handles, etc., has, since 1843, 

 largely increased, but is likely to be seriously 

 affected, as may various other industries, by what 

 is undoubtedly the most remarkable of these 

 miscellaneous vegetable products of the last half- 

 century, Celluloid. CELLULOID, or PYROXYLINE, 

 is vegetable fibre, cotton rags, paper-waste, or 



