390 NATURAL HISTORY OF PLANTS. 



and sereral PaulUnia and Serjania^ and it is from the embryo that the 

 fatty matter is extracted ; species with soluble gum like Koelreuteria 

 pamculata^(&g. 385-390) ; lastly, others are used to extract sugar from, 

 as Acer saccharinum ^ in North America, and with it, several other 

 species such as A. pensylvanicum ^ (fig. 418-420), rvhrum^ and erio- 

 carpum? Sugaris also contained in the sap of A. campestre,^ Pseudopla- 

 tanus^ and platanoides ; ^ but it is extracted much less frequently. In 

 Canada and the central parts of the United States, the trunk of the 

 Sugar Maple is notched, about March, with a large auger with 

 which two parallel holes are bored obliquely upwards at nearly half 

 a yard from the ground. By means of tubes of elder, the juice is 

 conducted into the receptacles placed at the foot of the tree ; it is then 

 evaporated at a very brisk fire. The liquor, on the removal of a scum 

 which forms, becomes syrupy, is filtered through woollen tissue, 

 and then poured into a crystallizing-pan, where a raw sugar is 

 obtained which may be refined like beetroot sugar and become 

 completely white. The flow of sap amounts to as much as 17 or 

 18 pints a day, for more than a month, and may produce from 

 a single stem four and a half pounds of sugar during that period. 

 The same tree may thus yield sugar for thirty years, provided that 

 by piercing the trunk in. different places each year, it is allowed to 

 repair its pith and wood.^ The Black Maple ^° of North America^ 

 closely allied to the preceding, is equally used. The other species 

 we have mentioned also contain sugar in their sap, but it is never 

 turned to account. Different species of Acer, as A. campestre, A. 

 platanoides, and A. ruhrum, have an astringent bark used for drying 

 and preparing skins. Several species are used for the extraction of 

 American potash, of which there is a large proportion, it is said, in 



1 See p. 417, note 4. wood, Auzeraule (Fr.), Little maple). 



2 L. Spec. 1496. — Miohx p. Arbr. ii. t. 15. — '' L. Spec. 1496. — Duham. Arbr. i. t. 36. — 

 Tratt. Arch. i. n. 3, o. ic. — DC. Prodr. i. 595, Gren. et Gode. Fl. de Fr. i. 321 (Great maple, 

 n. 19. — EosENTH. op. cit. 112. Sycamore, White maple). 



3 L. Spec. 1496.— .4. striatum Lamk. Diet. ii. ' L. Spec. 1496.— Ddham. Arbr. i. 1. 10, fig. 1. 

 381. — Gren. et GoDR. PI. de Fr. i. 322 (Plane, 



* L. Spec. 1496.— MicHx, op. cit. t. 14.— Pl^ne (Fr.), False Sycamore). 



Desf. Amu Mm. vii. 414, t. 26. ' Aveq. Joum. Pharm. et Chim. ser. 3, xxxii. 



* Miohx, Fl. Bor.-Amer. ii. 253.— Desp. he. 280.— Gura. Brog. Simpl. ed. 6, iii. 699 (this 

 cit. il%—A. dasycarpum "W. Spec. iv. 985 sugar is saccharose). 



(V^Tiite maple). '° Mickx, Arbr. ii. 238, t. 16.— DO. Prodr. n. 



6 L. Spec. 1497.— DC. Prodr. n. 8.— Gken. et 20. 

 GoDR. Fl. de Fr. i. 322 (Common maple. Warm 



