124 



NATURE 



[June ii, 1891 



and the description of the foot of the fly is of very special 

 interest. The wing-joint is described with great care 

 and thoroughness, in connection with the mechanics of 

 flight. 



Comparisons between insect and vertebrate structures 

 are made with great boldness. One example will prob- 

 ably astonish common-place niorphologists. Weismann 

 observed that the femoro-tibial part of the fly's leg forms 

 at first a mere lateral prominence, which is converted by 

 segmentation and constriction into a bent knee, the 

 upper part yielding the coxa and femur, the lower part 

 the tibia. Mr. Lowne confirms this account, and illus- 

 trates it by figuring five stages (Fig. 34). Next he com- 

 pares the lateral prominence to the exopodite of a biramous 

 limb. Then he adopts Dr. Gaskell's suggestion that the 

 limbs of an Arthropod may correspond to the visceral 

 arches of a Vertebrate. In the following sentence we 

 reach the climax. " The double character of the em- 

 bryonic appendages in the Crustacea, and in the maxillae 

 of insects, as well as in the thoracic limbs of the rudi- 

 mentary fly-nymph, is certainly very suggestive of the 

 double character of the pterygomaxillary arch, or even of 

 the hyomandibular in vertebrates." 



So much conscientious labour has been bestowed upon 

 this treatise, and it is so useful to the student of insect 

 anatomy, that it is a pity to see the text encumbered with 

 discussions which, to avoid dogmatism, we will merely 

 call extremely hazardous. Would it not be better to 

 bring out such views in another place, and leave the 

 magnum opus free of doubtful matter ? 



When all deductions have been made, the book must 

 be counted a valuble addition to the literature of the 

 subject. L. C. M. 



Races and Peoples : Lectures on the Science of Ethno- 

 graphy. By Daniel G. Brinton. (New York : N. D. 

 C. Hodges, 1890. Sold by Kegan Paul, Trench, 

 Triibner, and Co.) 

 The lectures of which this book consists were delivered 

 at the Academy of Natural Sciences, Philadelphia, early 

 in 1890. They present a good general view of the lead- 

 ing principles of ethnography, as these are understood by 

 the author. He begins with a discussion of what he calls 

 the physical and psychical elements of ethnography, next 

 treats of the beginnings and subdivisions of races, then 

 takes in order the divisions in which he arranges the 

 various groups of mankind, and finally deals with 

 problems relating to " acclimation," amalgamation, and 

 the influence of civilization on savages, and offers some 

 suggestions as to the destiny of races. The human 

 species seems to him to include five races — the Eur- 

 african, the Austafrican, the Asian, the American, and 

 insular and littoral peoples. Each of these is subdivided 

 into branches, stocks, and groups ; and an effort is made 

 to define the traits which, according to Dr. Brinton, the 

 members of each race have in common. It is not always 

 easy to understand the principle of his classification. 

 The Eurafrican race, for instance, includes the following 

 groups : Libyans, Egyptians, East Africans, Arabians, 

 Abyssinians, Chaldaeans, Euskarians, Indo-Germanic or 

 Celtindic peoples, and peoples of the Caucasus. These 

 peoples are all white ; and Dr. Brinton thinks we may 

 also say of them, "hair wavy, nose narrow." But the 

 differences by which they are separated from one another 

 are, at least in some cases, so profound, that it is ex- 

 tremely doubtful whether we are warranted in attributing 

 to them a common origin, except in the v»ide sense in 

 which a common origin is attributed to humanity gener- 

 ally. So long, however, as Dr. Brinton's classification is 

 understood to be merely a convenient way of bringing 

 together great masses of facts, it may be of considerable 

 service to students. The book embodies the results of 

 much careful research, and is written in a clear and 

 vigorous style. 



NO. I I 28, VOL. 44] 



LETTERS TO THE EDITOR. 



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

 pressed by his correspondents. Ntither can he undertake 

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

 7Tianuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.'] 



Crystals of Platinum. 



Since writing a note on this subject to Nature (vol. xliii. 

 p. 541) I have found that it is by no means requisite to use 

 topaz in order to obtain crystals of platinum from a ribbon of 

 that metal heated by a current. Thus the ribbon may be dusted 

 over with quartz dust, and if the temperature be raised to that 

 at which this is slowly melting (1430° C. about), crystals of 

 platinum gather upon projecting points on the quartz. Doubt- 

 less the presence of fluorine will facilitate, as described In my 

 former letter, the volatilization of the platinum, but there is 

 little doubt that at a temperature some 300° below its melting- 

 point (1750° ; Violle) there is a slow volatilization of the metal 

 due either to heat pure and simple, or to this in conjunction 

 with the presence of a current as in high vacua. 



To put the possibility of chemical action out of the question, I 

 weighed a clean ribbon of pure platinum, 9 centimetres in length, 

 and passed such a current through it, for 30 minutes, as raised 

 it to nearly the melting-point of palladium (1500° ; Violle). The 

 first weighing was o'oyoo grammes, the second (after heating) 

 o*o688, indicating a loss of 1 7 per cent, of its weight. 



I find that Prof. A. S. Tornebohm, of Stockholm, has de- 

 scribed in a recently-published paper {Aftryck nr Geol. Fdren. i 

 Stockholm Forhandl., Bd. 13, Haft 2, 1891) cubical crystals of 

 jjlatinum formed by the action of chlorine gas upon platinum 

 black at a high temperature. The figures illustrating his paper 

 depict crystals similar to those obtained by the present method. 



J. JOLV. 



Physical Laboratory, Trinity College, Dublin. 



Porpoises in the Victoria Nyanza. 



In Dr. Carl Peters's "New Light on Dark Africa," he speaks 

 of '-'some large gray-bellied porpoises tumbling about" in Lake 

 Victoria Nyanza, ' ' and rollicking in the tepid flood " (see p. 445). 



I should be glad to know whether there is any other authority 

 for the occurrence of a Cetacean in this lake. It is possible, 

 but very improbable, as no Cetaceans are known to occur in the 

 Nile, or other African fresh waters, although there has been a 

 report of the Manatee being found in the Shari, which runs into 

 Lake Tchad (see Barth, " Reisen," iii. p. 289), and the Manatee 

 also occurs in the Niger. P. L. Sclater. 



The Zoological Station at Naples. 



It is desirable that the names of any biologists who wish to 

 make use of the British Association Table at the Naples Zoo- 

 logical Station, during the year commencing in September next, 

 should be in the possession of the Committee before the meeting 

 of the British Association at Cardiff. 



Intending applicants are therefore requested to send in their 

 names, and a statement of the nature of the work they pro- 

 pose to undertake, before June 30, to me as Secretary to the 

 Committee. W. Percy Sladex. 



13 Hyde Park Gate, S.W., June 6. 



A BRITISH INSTITUTE OF PREVENTIVE 

 MEDICINE. 



ON Friday, June 5, Sir Michael Hicks-Beach received 

 in one of the large rooms of the Victoria Hotel, 

 Northumberland Avenue, an unusually numerous and 

 influential deputation on behalf of the British Institute of 

 Preventive Medicine. Sir Michael Hicks-Beach was 

 accompanied by Sir Henry Calcraft, K.C.B., Secretary to 

 the Board of Trade, Mr. Courtenay Boyle, C.B., and Mr. 

 Walter J. Howell. 



Among the members of the deputation were the Duke 

 of Westminster, the Earl of Feversham, Sir Frederick 

 Abel, Sir F. Bramwell, Sir John Lubbock, Sir Benjamin 



