268 



NA TURE 



[July 23, 1908 



mainland. Dr. H. Schenck is responsible for the 

 account of the Canary Islands, as he was for the pre- 

 vious numbers referring to the islands of Kerguelen, 

 St. Paul, and New Amsterdam ; but much of the text 

 and a few of the illustrations are again the work of 

 the late Prof. A. F. W. Schimper, who was botanist 

 to the expedition. The character sketches written by i 

 Prof. Schimper bear that particularly vivid impress 

 and breadth of view that characterise " Die Pflanzen- 

 geographie. " Certainly he has a most fascinating sub- 

 ject, as the flora of the islands is rich in curious 

 endemic plants. 



The zones of vegetation as developed on the island 

 of Teneriffe are fairly typical for the group. Schimper 

 distinguishes three regions, basal, montane, and 

 alpine. The basal region is the most extensive ; here 

 are found the weird arboreal monarch of the island, 

 Dracaena Draco, the dragon's blood tree, showing at 

 first an unbranched stem with tiers of horizontal 

 leaves, but developing later a much-branched svstem ; 

 the candelabra-like EiipJiorkia canariciisis and a date 

 palm, Phoenix Jtibae, the fruits of which provide food 

 for birds but not for man. These are the dominant 

 endemic species, but there are many others, succulent 

 species of Euphorbia, Ceropegia, Echium, &c., and 

 xerophytes characterised by a mass of thin, whip-like 

 branches and narrow leaves, of which Plocama penduJa 

 furnishes a type. The proportion of endemics in the 

 coastal vegetation is about one-third, a large number 

 being species of Statice. 



In the montane region Schimper notes particu- 

 larly the laurel forest, where Laurus canariensis. 

 Erica arborea. Ilex canariensis, and Ocotea bullata 

 hold sway. Great interest attaches to several of these, 

 because they are evidently closely connected with Ter- 

 tiary fossil forms found in European countries. 

 Pinus canariensis gives character to the landscape at 

 5000 feet, while higher Spartocytisits siiprantibiiis is 

 almost the sole occupant of the black, stoney slopes. 

 The volume is altogether un embarras de richesse, 

 with copious illustrations, some in heliogravure, 

 others interspersed with the text. Not the least pleas- 

 ing feature is the generous manner in which Dr. 

 Schenck has subordinated his work to that of his 

 former colleague. 



The study of phytoplankton is, for obvious reasons, a 

 more exclusive subject, but the results given in the 

 two volumes of text and plates are full of interest. 

 Two earlier accounts treated of the gatherings taken in 

 the .Antarctic and .Atlantic, while the plankton of the 

 Indian Ocean is here under discussion. It was found 

 that a definite limit to the Antarctic region could be 

 set at Kerguelen Island. As the ship proceeded north- 

 wards the character of the plankton changed, species 

 of Ceratium and Peridineae generally becoming more 

 numerous. Off Sumatra an increase of diatoms and 

 Schizophyceffi connected with the increased food supply 

 furnished evidence of coastal plankton mixed with 

 the oceanic forms. Respecting vertical distribution, it 

 was noted that in tropical waters the mass of plank- 

 ton exists in the upper six hundred feet, w-hile at 

 twelve hundred feet living forms practically cease. 

 The morphological details at the end of the volume 



NO. 2021, VOL. 78] 



include notes on diatom microspores, the formation of 

 the rays in certain of the Peridineae, and some life- 

 histories. .\ final word of commendation must be 

 bestowed on the volume of exceptionally fine drawings 

 that have been skilfully reproduced. 



SOME .VEIF CHEMICAL BOOKS. 

 (i) .4 Systematic Introduction to Analytical Chemistry. 

 Bv .A. F. Walden and B. Lambert. Pp. vl + 176. 

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{2) Xatinlchrc jnr hohere Lcliranslaltcn. I. Teil. 

 Chemie, Mincralogie, und Geologie. By Dr. F. 

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(3) Organic Chemistry. Including certain portions of 

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(4) Stereochemic, die Lehre von dcr Riitimlichen 

 .Anordnung dcr Atonic im Alolekiil. By Dr. L. 

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 1907.) Price 5 marks. 



(i) A LTHOUGH there is perhaps no branch of 

 ■t\ chemistry which at the present day is more 

 stagnant than analysis (of the academic as distin- 

 guished from the technical kind), there are always to 

 iDe found teachers whose interest in the subject will 

 prompt them to publish their experiences. With this 

 interest we have the greatest sympathy, for there is 

 no doubt that the skill, neatness, intelligence an<i 

 patience which analysis demands will always appeal to 

 the chemist. .Analysis is, in fact, his handicraft, just' 

 as much as the using of a lathe or a planing machine 

 is that of the mechanical engineer, with this differ- 

 ence : that whilst the engineer may employ a mechanic 

 to do his practical work, the chemist must always 

 be his own analyst. 



When we approach the question of the place of 

 analvsis in chemical teaching, we put the subject at 

 once on a different plane and see it in a different per- 

 spective, for as students of chemistry are not all to 

 be professional chemists, we have to consider analysis 

 as merely a part of chemical teaching. There is no 

 doubt that there has been a tendency for the subject 

 to assume an exaggerated value. We inherited the 

 tradition of the Stockholm Laboratory, and continued 

 it because it adapted itself to practical examinations 

 in chemistry. We do not believe any more than the 

 authors " that the neglect of qualitative analysis is 

 either necessary or desirable," but there is a great 

 difference between learning the principles of the pro- 

 cess and studying it as a part of the technique of the 

 professional chemist. For the ordinary student there 

 seems no object in discovering and identifying such 

 uncommon combinations as meta- and pyro-phosphoric 

 acid, fluosilicates or perchlorates. The range of 

 practical chemistry has so increased of late that it 

 has become more than ever imperative to restrict the 

 study of one branch if it encroaches on the time which 



