THE ROMANCE OF OUR TREES 



the odour is not eradicated for a day or more. This 

 penetrating offensive smell is due to a peculiar crys- 

 talizable, fatty acid, akin to butric acid, which was 

 first extracted about 1830 and named ginkgoic acid. 

 When extracted it forms tufts of acicular crystals, 

 brownish yellow in colour. It is easily soluble in 

 alcohol or ether and in either case exhibits a strong 

 acid reaction; when heated with a solution of potash 

 it forms a soap-like compound. I do not know if 

 any attempt to use this ginkgoic acid in the arts and 

 sciences has been made. 



The nuts, denuded of their offensive pulp and 

 washed, are pure white, and are on sale in most of 

 the market towns in China and Japan and in a less 

 degree in those of Manchuria and Korea. They are 

 known in China as "Pai-kuo" or "Yin-kuo" (white or 

 silver nuts) and, after roasting, are eaten at banquets, 

 weddings, and convivial gatherings generally, being 

 supposed to promote digestion and to diminish the 

 effects of wine. There is told a story of their being 

 introduced, on one occasion at least, by Chinese to a 

 mining camp in north Australia, rubbed with some 

 bad scent to imitate Tonquin beans and sold as 

 such. Their avowed virtue was to destroy moths 

 but for such purpose they and also the true Tonquin 

 Bean (the seed of Dipteryx odorata, a tree native of 

 Guiana and belonging to the Pea family) are equally 

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