AGRICULTURAL BOTANY. 247 



to be very remarkable, that a country like China — rich in textile fibre, oils of many kinds, 

 vegetable tallow, dyes, and no doubt many other articles which have not come under my 

 notice — should afford so few articles for exportation. I have no doubt that as the country 

 gets better known, our merchants will find many things beside silk and tea, which have 

 hitherto formed almost the only articles exported in quantity to Europe and America. 



Two new Fibres from Brazil. 



There have been recently imported into England, from Bahia, two varieties of vegetable 

 fibre, which are new to commerce. One of them is, commercially speaking, a species of 

 flax, and is proposed to be used in the same way as that material. It is in small hanks, 

 about twelve inches in length : the individual fibres are remarkably fine, and have a peculiar 

 appearance, somewhat resembling a long staple sheep's wool. The color is a pale green. 

 This material was imported experimentally, and was called "tecum." Upon comparing it 

 with a specimen in the "Collection of Liverpool Imports," says Mr. Archer, I am led to 

 imagine that it is the produce of a palm-Zea/. The price stated in the foreign invoice is 

 equivalent to eighteenpence per pound. 



The other article is a very coarse red fibre, of considerable length, resembling the asta 

 bark in Dr. Royle's collection of Indian vegetable fibres : it is evidently, I think, says Mr. 

 Archer, the fibrous portion of the bark of some tree, probably an acacia. This material was 

 also sent from Bahia, and its application as a substitute for oakum was suggested. 



Sir William Hooker, who has examined this last fibre, pronounces it to be the product of a 

 noble tree, the seeds or nuts of which are well known to commerce as the " Brazil-nut." The 

 bark is beaten into oakum, and in this form is much used for caulking ships at Para. 



On the Oblique Direction of the Ligneous Fibre, and the Twist of the Trunks 



of Trees occasioned thereby. 



At a recent meeting of the Academy of Berlin, the following paper, on the above subject, 

 was presented by Prof. Braun: — 



The twist of the wood of many trees is a phenomenon well known to wood-cutters, shingle- 

 makers, carpenters, and others, but almost entirely neglected by botanists. The distinguished 

 geologist, the late Leopold von Buch, appears to have first directed the attention of scientific 

 men to it; and De Candolle, in his Organographie, (1827,) was the first botanist who spoke 

 of it. Most trees show this obliquity of the woody fibre more or less. In certain species 

 the twist is almost uniformly in the same direction ; in others, both directions occur with 

 about equal frequency, while in not a few no twist is distinctly observable. Sometimes the 

 same direction prevails in the majority of the species of a genus, or even of a whole family; 

 in other cases, opposite directions occur in the same genus or family ; and it is curious to 

 remark that in some instances nearly-allied species of Europe and America twist in opposite 

 directions. In a few instances, the fibre of a young tree is twisted in one direction ; that of 

 the old tree, in the opposite direction. 



In speaking of the direction, it is necessary to come to an understanding, first of all, as to 

 what we mean by right or left, a distinction attended with more difficulty than would appear 

 possible. Prof. Braun follows De Candolle and others in viewing the twist or coil objectively, 

 imagining himself in the centre of the coil, i Thus viewed, the bean-vine turns to the left, 

 the hop-vine to the right, &c. Linnaeus and others, however, have adopted the opposite or 

 subjective view, and regard the bean and other leguminous plants as turning to the right, as 

 they appear to an observer standing before the coil. The twist of the fibre may be discerned 

 in splitting the wood, or in its cracks when the bark is stripped off, or in the course of the 

 fissures made by lightning. Very often the bark itself, at the angles or superficial lines of 

 the trunk, indicate the direction of the wood within very distinctly. We make a few extracts 

 from one hundred and sixty-seven species observed. 



No manifest twist has been observed in species of Fagus, Juglans, and Carya, either in 

 Europe or America, nor in Ulmus, Ailanthus, Fraxinus, Acer dasycarpum, Gleditschia, or Robinia, 



