1 



248 



NATURE 



[January 10, 1901 



positive (right-handed) and some negative (left-handed). 

 If / is the translation, and^o o"^ value of the pitchy 

 the general value oi p is given by 



I _ I _l_ 2«7r 



J. D. Everett. 



CULTIVATION AND MANUFACTURE OF 

 TOBACCO. 

 Le Tabac Culture et Industrie. By E. Bouant. Pp. 

 xii + 347. (Encyclopedie Industrielle, Paris: J. B. 

 BailH^re et fils, 1901.) 



THE object of this work, as stated by the author in 

 the preface, is to describe in popular scientific 

 language the long series of operations necessary to trans- 

 form a tiny seed into a good cigar or a pinch of scented 

 snuff. 



In a short introduction the author gives a resume of 

 the best ascertained facts concerning the origin of 

 tobacco, its introduction into Europe, the prohibitions 

 intended to hinder its use, and the change of tactics 

 which have resulted in making the smoker contribute his 

 quota to the public revenue. 



Of the three parts into which the book is divided, 

 the first two deal with the cultivation and manufacture 

 of tobacco, and in the third part the economic, fiscal 

 and hygienic aspects of tobacco are discussed. 



In France the State controls the cultivation, and has 

 the monopoly of the manufacture of tobacco ; the author 

 restricts his treatment of the subject almost entirely to a 

 description of the methods of culture and manufacture 

 followed in France. 



Part i. commences with the botany of the principal 

 species of Nicotiana and with a short account of the 

 chemistry of tobacco. According to the analyses given 

 on p. 24, tobacco ash contains a large proportion of 

 salts of sodium (16 per cent, in the ash from the leaves 

 of Havana tobacco). This is at variance with the general 

 experience, for it is a remarkable and well-established 

 fact that tobacco contains very little soda in any form. 



The subject of culture is dealt with very fully, and a 

 large amount of information is given concerning the 

 choice of the most favourable soils and manures, the 

 rotation of crops, sowing and transplanting, the various 

 field operations during growth and ripening, and the 

 final operations of harvesting, curing and packing. 



In view of the experimental cultivation of tobacco 

 which has been carried on in Ireland during the past 

 season, it is interesting to note that the experience gained 

 in France shows that Europe will never be able to dis- 

 pense with American tobacco, as, with rare exceptions, 

 European varieties are inferior in aroma and combusti- 

 bility to those of American origin. 



The manufacturing methods described in the second 

 part are those employed in the great State tobacco fac- 

 tories of France. The methods of manufacturing cut 

 and roll tobacco and snuff differ materially from those 

 followed by British manufacturers, the result, no doubt, 

 of the different fiscal regulations in the respective coun- 

 tries. The methods employed for making cigars and 

 cigarettes, on the whole, are the same in both countries. 

 NO. 1628, VOL. 63] 



The book is well illustrated and, with the exception 

 of a few photographic reproductions which leave much 

 room for improvement, the illustrative figures are good 

 and clear ; typographical errors are not numerous. 

 Altogether it is a very readable work, and, in addition to 

 being interesting to the general reader, it should be of 

 some service to those engaged in the cultivation and 

 manufacture of "our holy herb Nicotian." J. W. 



OUR BOOK SHELF. 



Briefwechsel zwischen Franz Unger und Stephan 



Endlicher. Herausgegeben und Erlaiitert von G. 



Haberlandt. Pp. v. -f- 184. (Berhn : Borntraeger, 



1899.) 

 After the death of Unger's surviving son and daughter, 

 a large portion of his correspondence was presented to 

 the Botanical Institute of the University of Graz. From 

 amongst these remains Prof. Haberlandt gives to the 

 world the almost complete series of letters which passed 

 between Unger and Endlicher from 1829 to 1847. 

 There are 139 letters in all, of which about two-thirds 

 are by Unger. Though the correspondence is, in large 

 part, concerned with their own botanical labours, all the 

 more important contemporary contributions to Botany 

 are discussed between the friends. At the date of the 

 opening of this correspondence, neither of the writers 

 held an independent botanical post. Unger, who had 

 deserted the law and qualified in medicine, in 1830 

 became a medical officer at Kitzbiihel, in the northern 

 Tyrol. Here, during his five years' sojourn, he collected 

 the material for and wrote his now classic " Einfluss des 

 Bodens auf die Vertheilung der Gewachse." This was 

 the first attempt at a physiological flora, and Unger was 

 justly proud of his achievement. This and other work 

 paved the way to the professorship at Graz, to which he 

 was appointed in the autumn of 1835, ^^^ which he held 

 till Endlicher's death. Endlicher, the author of the well- 

 known " Genera Plantarum," was made keeper of the 

 botanical department in the Hof Museum, at Vienna, 

 within a few months of Unger's appointment to Gra/u 

 Many common undertakings were mooted between the 

 friends, and the most notable of those which reached 

 accomplishment was their joint " Lehrbuch der allge- 

 meinen Botanik," published in 1843. ^ts inception and 

 progress are very fully set forth in the letters, and this 

 portion of the correspondence will be read with interest 

 as effectively contrasting the character and temperament 

 of these two men. That Schleiden should have chosen 

 the same time to bring out his remarkable " Grundziige 

 der wissenschaftlichen Botanik " was an event which could 

 not fail to impress the joint authors. Unger, with charac- 

 teristic outspokenness, writes : — " What do I think about 

 Schleiden ? He is an excellent fellow, though I don't 

 agree with him entirely. We have wanted a man like 

 this for a long time. It is by him— not by us — that a new 

 epoch is created in our science." Another part of the 

 correspondence, that relating to Unger's discovery of the 

 ciliated zoospores of Vaucheria, is also full of interest. The 

 headstrong and enthusiastic Unger insists on announcing 

 his discovery in the form of a series of popular letters 

 under the title " The Plant at the Moment of becoming 

 an Animal," with -an absurd quotation from Oken (the 

 nature-philosopher) as motto. This intention draws from 

 Endlicher one of the best letters in the book (No. 100) ; 

 but it is quite lost upon Unger. 



The correspondence is preceded by an able apprecia- 

 tion of the two botanists by Prof. Haberlandt, the present 

 occupant of Unger's chair at Graz ; whilst, by way of con- 

 clusion, there is printed a series of documents which tends 

 to show that Endlicher died a natural death and did not 

 commit suicide, as has been generally believed. 



