246 



NA TURE 



[January 15, 1903 fe 



Hartig, Nordlinger, Laslett and Marshall Ward preceded 

 it may be a safe surmise, but the author has done his work 

 much in his own way, and, on the whole, has done it 

 well, and acknowledges his indebtedness to the above 

 and to other writers. The longest section, that on the 

 sources, characters and uses of the woods of commerce, 

 which occupies more than two hundred pages of the 

 three hundred and fifty composing the book, abounds in 

 interesting facts about the foreign and colonial timbers 

 now so largely imported into this country, though why 

 the word " Acacia," on p. 141, is limited to " Robinia"and 

 " Eucryphia " is the more puzzling since the author shows, 

 on p. 341, that the wattles of Australia are the true plants 

 of that genus. 



The sections on the recognition and classification of 

 woods, on seasoning, on the supplies of wood and on 

 testing are also good ; those on the origin, structure and 

 development and on the defects of wood are less so. 

 Indeed, the whole subject of the microscopic structural 

 characters is very poorly treated, and the appendix on the 

 microscopic examination of wood might as well have been 

 omitted. This is a pity, since it is just in this direction 

 that so much interesting and important work has been 

 done of late, and the author's meagre treatment of this 

 theme and his omission of any mention of the publica- 

 tions of Muller, Mer, Strasburger and other investigators 

 suggest that he is here on unfamiliar ground. Moreover, 

 certain slips, such as the confusion of the schlerenchyma 

 of a peach stone with wood (p. 2), the denial of wood to 

 the so-called herbaceous plants and the retention of the 

 term "exogenous" (p. 3), the inadequate treatment of 

 cellulose (p. 6), the denial of trachea: to the protoxylem 

 of Conifers (p. 19) and the explanation of the term 

 "desmogen," are signs pointing to the same conclusion. 



On the other hand, there are some capital photographic 

 reproductions of the appearances of various woods in 

 transverse sections, and the material is well arranged 

 and rendered accessible by what appears to be a very 

 complete index. 



L' Ea.it dans T Alimentation. By F. Malmejac. Pp.312. 

 (Paris : Felix Alcan, 1902.) Price 6 francs. 



It is quite true, as the author of this work states, that 

 the great problems connected with the purification of 

 water and its safety or danger when used for drinking 

 purposes are not yet solved, but although he claims — 

 and not without reason — that his work is something more 

 than a compilation, inasmuch as it contains results of 

 special study on the points which have appeared to him 

 the least clear or the more controversial, the reader who 

 has studied, say, the works by Thresh or Mason on the 

 subject will find little to learn from the present volume. 



The work is certainly a useful and interesting one, but 

 it scarcely justifies the eulogistic preface written by M. F. 

 Schlagdenhauffen, honorary director of the Higher 

 School of Pharmacy of Nancy, from which the reader 

 would conclude that the present volume was almost an 

 epoch-making contribution to an important subject. 



The book is divided into five parts, which are sub- 

 divided into chapters. The first part deals with water 

 in general, including the microscopic, the chemical and 

 the bacteriological examinations, and the other four 

 parts deal with the organic matter of water, the germs of 

 water, the filtering value of different earths and the 

 purification of water. 



Our Dogs' Birthday Book. Arranged by Mrs. F. H. 

 Barnett. With Twelve Pictures of Champion Dogs. 

 Pp. 144. (London : George Allen, 1902.) 



A birthday book of the familiar kind, except that the 

 quotation under each day of the year is concerned with 

 dogs. 



NO, 1733, VOL. 67] 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended Jor this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



The Hydrographical Work of the North Sea Investi- 

 gation Committee (Scotland). 



In weather of exceptional severity, Lieutenant and Com- 

 mander Sharp, of H.M.S. Jackal, has just brought his second 

 hydrographical cruise to a successful issue. The Jackal left 

 Aberdeen on December 4, and followed approximately the same 

 course (on lines laid down by Mr. H. N. Dickson) as on her 

 autumn cruise in August-September (cf. Nature, October 

 30, 1902), that is to say, northwards to Lerwick, thence 

 in a north-easterly course to near the Norwegian coast, then 

 westward to Faeroe and back along a somewhat more 

 southerly track, passing between Shetland and Orkney and 

 out into the North Sea as far as the meridian of o°. The last 

 observations were made on December 15. About 125 water- 

 samples were obtained at various depths, in full series, at twenty 

 stations, and surface samples were collected in addition hour 

 by hour. Captain Sharp bore, on this occasion, the whole re- 

 sponsibility of collecting the samples and observing the tempera- 

 tures, and I venture to think that, in spite of the worst possible 

 weather, he has achieved remarkable success. The water- 

 samples are being estimated in the laboratory of my colleague, 

 Prof. Walker, and when this work is done, the whole of the data 

 will be handed over to the hydrographers ; but the temperature 

 records are in themselves interesting, so much so that I think it 

 right to publish them in the following brief abstract. 



The stations were as follows (numbered according to those 

 of the August cruise with which they approximately corre- 

 spond :— ii., 58° 36' N., I°46' W. ; iv., 59° 17' N., 1° 30' W. ; 

 vi., 60° 37' N., o' 30' E. ; vii., 6i Q 12' N., 1° 52' E. ; viii., 61° 

 40' N., 3° 4' E.; ix., 61° 39' N., 2° o' E.; x., 61° 38' N., 0° 33' 

 E. ; xi., 61° 50' N., 1" o' W. ; xii., 61° o' N., 1° 18' W.; xiii., 

 61° 10' N., 2° 9' W. ; xiv., 61 23' N., 3° 25' W. ; xv., 61 "38' N., 

 4° 39' W. ; xvi., 6l° 44' N., 6" 3' W. ; xvii., 61° 13' N., 

 6° 34' W. ; xviii., 6o° 53' N. , 5° 30' W. ; xix. , 60° 35' N., 

 4° 26' W. ; xx., 6o° 13' N., 3° 9' W.; xxi.', 59° 40' N., 1° 

 15' W. ; xxii., 59' 32' N., o 2' E. ; xxiv., 58° 53' N.,o° 25' W. 

 To take first the surface-temperatures. These fluctuated 

 much in the first part of the course from the entrance of the 

 Moray Firth to Lerwick. Starting at 7°'5, the temperature rose 

 opposite the Pentland Firth to S"'S, fell off the Orkneys to 6° b, 

 rose again in the neighbourhood of Fair Isle to 9° 3, and after 

 falling as low as 5'4, rose to 8°'4 at Lerwick. Similar tem- 

 peratures (S'^-S ^) were then met with as far as Station vii., 

 after which point there was a rapid rise to 9°'6, followed by 

 an exceedingly sudden drop to 6°'6 (the salinity dropping from 

 about 35°'3 to 32 J- 6) near Station viii., off the Norwegian coast. 

 Running westward, temperatures ranged in the neighbourhood of 

 9°'5 all the way to the middle of the Faeroe Channel, and then 

 dropped between Stations xiv. and xv. to f~ at the latter point. 

 They rose again as Faeroe was approached, to 8° or a little 

 less ; and on the homeward and more southerly course, a colder 

 current was again crossed, this time in a broader and apparently 

 double belt, between 4° and 5° W. longitude, with temperatures 

 of 6°'6 to6°"8. Eastward of 4 W., a rapid rise took place to 

 8°'9, rising further to 9° - 4 a little to the east of 3 , and there- 

 after the curve fell, with considerable fluctuations, to about 8" 

 at the limit of Station xxii. (o 2" E. ). 



Passing to the deep-water temperatures, we have, on the 

 line from the Moray Firth to Lerwick (Stations ii. , iv. and xxi.), 

 everywhere warmer underlying colder water, the readings at o 

 and 100 metres being respectively 8° - 2-8°'S, 8 D "S-9° and 8°- 

 8°-6. 



Between Lerwick and the coast of Norway, we have firstly at 

 Station vi. slightly irregular readings, falling from 8°'5 at the 

 surface to 8° '2 at. 130m. ; at Station vii., the surface-water of S°'3 

 has underneath it warmer water to 8° - 85 at 60 m. , cooling to 

 8°'65 at 140 m. ; while at Station viii. , a broad zone of similarly 

 warm water underlies the very cold (6°'7) surface-layer (6' "05 at 

 20 m.), giving us readings of 8°'3 at loom., S°'7 at 200m., 

 below which level the temperature falls again to 6 C '0, at 380 m., 

 near the bottom. Turning westward, we have at Station ix. 



