NA TURE 



55; 



THURSDAY, APRIL ]6, 1903. 



ECONOMIC VEGETABLE PRODUCTS.. 

 Die Rohstoffe des Pflanzenreiches. By Dr. Julius 

 Wiesner. Second Edition. Ten parts. In two 

 volumes. Pp. xi + 795 and vi + 1070. (Leipzig : 

 Engelmann, 1900-1903.) Price 3/. 



THE vast importance of an accurate knowledge of 

 the raw materials of vegetable origin must be 

 so patent to everyone as to give rise to the. thought 

 that the number of text-books on the subject must 

 necessarily be very large. From the vast and ever-in- 

 creasing colonies of this country huge quantities of 

 material of the most varied description, and almost 

 incalculable value, are annually poured into its markets. 

 Hundreds of different kinds of timbers, fibres, gums, 

 resins, dye-stuffs, tanning materials, &c, are brought 

 hither to be devoted to various technical uses or to be 

 distributed to other countries. Very frequently, too, 

 specimens of drugs and other products are sent from 

 abroad accompanied by queries as to their quality, uses 

 and value ; such queries are generally addressed to 

 brokers or to the sender's private friends. It is 

 therefore evidently a matter of primary importance 

 that these products should be investigated and classi- 

 fied, their uses examined into, and the means bv which 

 their identity and purity may be established should be 

 determined and recorded. A lexicon or handbook 

 might thus be compiled which would be of inestimable 

 worth to those who deal in or use such vegetable 

 products, and might be the means of introducing valu- 

 able substances, or even of establishing new industries. 

 It is in England of all countries where one would ex- 

 pect to find properly staffed institutions where such 

 investigations would be carried out, and where men 

 would be trained for such work ; in England, unfortu- 

 nately, this study is much neglected, although the 

 conditions are more favourable than elsewhere. 

 Museums with large collections of economic products 

 exist, but they remain for the most part a mass of 

 unsifted and undigested material. An effort in the 

 right direction has, it is true, been made in the Imperial 

 Institute, which, properly encouraged and extended, 

 may yet yield valuable results. 



It is remarkable that Austria should be the country 

 in which the study of economic vegetable products has 

 been most sedulously pursued. The first edition of 

 Prof. Wiesner 's " Rohstoffe des Pflanzenreiches " was 

 published in Vienna in 1873, but since that time the 

 field has so rapidly increased in extent that the author 

 found it necessary, in preparing a second edition, to 

 invite the cooperation of a number of his colleagues, 

 each of them a specialist in his particular department. 

 Amongst these the names of Hanausek, v. Hohnel and 

 Vogl may be mentioned as a sufficient guarantee of the 

 excellence of the work thus contributed. No better 

 plan than this could have been followed; it has been 

 adopted in other works with conspicuous success. 



The subject-matter is divided into twenty-three 

 sections, of which, perhaps, those dealing with the 

 NO. I/46, VOL. 67] 



gums, resins, vegetable fats, starches, barks, woods 

 and fibres are the most important, comprising, as they 

 do, some 1135 pages out of 1822. The classification 

 of the substances dealt with rests, therefore, upon a 

 scientific basis, and is no doubt the best that could 

 have been adopted, though it has the disadvantage of 

 disregarding the uses to which the various products 

 are put; materials that are used in any particular 

 industry are therefore often scattered throughout the 

 work, an inconvenience which might easily be remedied 

 by the introduction of lists of the substances tabulated 

 according to their uses. 



The arrangement of each section may be illustrated 

 by a short description of one of the most important, 

 viz. the resins, which covers some 200 pages, and has 

 been written by Profs. Wiesner and Bamberger. Com- 

 mencing with a description of the characters of resin 

 generally, the authors pass to the consideration of the 

 physical characters of the resins, and then deal with the 

 chemical composition of such as have been investigated. 

 Following upon this is a long list of plants, mostly 

 trees, from which resins have been obtained, and lastly, 

 a detailed account of each of the more important mem- 

 bers of the group. Considerable attention has been paid 

 to the appearance of the interior, as well as the exterior, 

 when examined under the microscope, the various 

 lines, fissures and other markings that make their 

 appearance during the drying and weathering of the 

 resin being described. Many of these appear to be 

 characteristic, but they are not always easy to discern. 



The formation of the resins in the cells in which they 

 are produced, and especially the pathological formation, 

 whether intentionally or accidentally induced, is, how- 

 ever, briefly treated. This is somewhat a matter for 

 surprise. Recent researches have shown that certain 

 valuable resins and oleo-resins are pathological pro- 

 ducts the formation of which is artificially induced, 

 and it remains to be seen whether in other cases a 

 similar formation or increase of production cannot be 

 brought about, a problem of great economic import- 

 ance. 



The chemical composition is well brought up to date, 

 all the recent investigations of Prof. Tschirch and his 

 pupils having been thoroughly sifted. 



The sections on fibres, by Prof. Wiesner himself, 

 and on woods, by Prof. Wilhelm, both very important 

 subjects, are most completely and attractively dealt 

 with. More than 100 different kinds of timber are de- 

 scribed, and many are illustrated by woodcuts of their 

 transverse sections. In both of these sections the 

 hand-lens and the microscope play, as may be im- 

 agined, a very important part. A useful adjunct to 

 each of these sections would be an analytical key by 

 which an unknown member of the class might, within 

 certain limits, be identified. 



The starches form another group that has received 

 detailed treatment. The formation of starch, its 

 chemical composition and the changes it undergoes 

 when hydrolysed, are very thoroughly discussed. The 

 groups of catechus, india-rubbers and vegetable fats 

 have been dealt with by Prof. Mikosch, and somewhat 

 more briefly, considering their great technical import- 

 ance, than the other sections of the work. 



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