August 9, 1900] 



NATURE 



351 



A SUGGESTIVE paper on the driving energy of physico- 

 chemical reaction and its temperature-coefficient is contributed 

 to the Proceedings of the American Academy of Arts and 

 Sciences, xxxv. 23, by Prof. Theodore William Richards, in 

 which the author, starting with the close similarity between the 

 equations of Clausius and van 't H off, dYn.PldT=\IRT^ and 

 d\aK'IJT= UlRT^i points out the advantages, previously recog- 

 nised by Arrhenius, of regarding pressure to be the fundamental 

 quantity which determines the progress of chemical reactions, 

 as this aspect aff'ords a more direct method of analysis than 

 the study of volume, concentration or entropy. An expression 

 called the "reaction met.atherm" is evolved, which represents 

 in terms of pressure the temperature-coefficient of the equilibrium 

 ratio of ideal physico-chemical reaction. The equation obtained 

 is the mathematical expreision of the theorem of Maupertuis or 

 Le Chatelier, and when analysed it shows that the part played 

 by each substance in a reaction miy be considered as the 

 logarithm of the product of its " physico-chemical potential " 

 and its actually present pressure. The reaction metatherm may 

 be simplified into a reaction-isobar and a reaction-isochor, ac- 

 cording as the pressure or volume is kept constant during the 

 reaction. While, however, the reaction-isobar offers the most 

 convenient basis for calculations to which it is applicable, results 

 under constant volume are more conveniently calculated if the 

 reacting substances are expressed in terms of concentration 

 according to the equation of van 't Hoff. 



THEiconogr.iphy and anthropology of the Irano-Indi.ins is the 

 subject of a recent study by M. Ujfalvy in the current volume 

 of r Anthropologie. He concludes that the ancient Persians had 

 a narrow-faced, dolichocephalic, somewhat flattened head re- 

 sembling that of the ancient Hindus. They were all fair or 

 reddish, and closely resembled the Macedonians of Alexander. 

 It is impossible to say whether this was the primitive Persian 

 type ; at all events, it was their well-characterised type six cen- 

 turies before our era. Two centuries later the typa began to be 

 slightly modified. This took place in the interval between the 

 decline of the dynasty of the Achemanides (328 B.C.) and the 

 rise of that of the Sassanides (240 a.d. ). This alteration was 

 probably due to the Semites of Elam and Syria, and to the 

 Turanians of Babylon. The former influence did not affect the 

 dolichocephaly, but it slightly increased the height of the head, 

 and modified the nose considerably. The latter influence 

 shortened the head, and but slightly modified the face. The 

 Sassanide warriors exhibited the new complex type. At the 

 close of the Sassanide period the Arabs reinforced the Semitic 

 characters. M. Ujfalvy accepts and reinforces Houssay's dictum 

 that, in a mixture of Aryans with Mongols or Mongoloids, the 

 latter lose their facial characters, flattening of the nose, promi- 

 nence of the cheek-bones, absence or sparseness of the beard ; 

 but, in exchange, they impose the shape of their skull on the 

 former. 



Messrs. Swift and Sox have just patented a very handy 

 little electric lamp for microscopic purposes. The lamp — a 

 16 candle-power one — is enclosed in a metal cylinder, the inner 

 surface of which is painted white. The light makes its exit 

 through a circular aperture in the side of the cylinder near its 

 free end ; the end is closed by a plate set at an angle of 45' 

 and painted white, so as to reflect the light through the circular 

 aperture. The light thus does not pass direct from the 

 incandescent carbon filament to the mirror of the microscope, 

 but is reflected from the white walls of the cylinder. In this 

 way a very even illumination is obtained, which is more uniform 

 than that obtained from the average ground glass lamp. While, 

 however, the light given by this lamp is admirably suited for 

 the ordinary powers such as are attached to the average student's 

 microscope, it is, in our opinion, neither powerful enough nor 

 white enough for high-power work, this being a defect common 



NO. 1606, VOL. 62] 



to all electric microscope lamps. Where in addition a lamp is 

 required for dissection purposes, as is so often the case, the 

 direct light of the ordinary type of electric lamp will be found 

 more suitable. This lamp is very compact and steady, and its 

 movements, especially those about its horizontal axis, are parti- 

 cularly easy and steady. 



The Botanical Museum of Florence has recently received a 

 donation of considerable interest in connection with the history 

 of botany in Italy, viz. the collections made by Micheli, by 

 Bruno Tozzi, and by G. Targioni-Tozzetti in the i8th century, 

 including the type-specimens of species named by these and 

 other eminent botanists. The donation includes also Micheli's 

 and Targioni-Tozzetti's collections of sea-weeds. 



In No. 4 of vol. xxi. of Notes from the Leyden Museum, 

 Dr. J. BlUtikofer, the director of the Zoological Garden at 

 Rotterdam, records the birds collected by the Dutch expedition 

 to Central Borneo. Testimony is borne to the thoroughness of 

 the work of the English naturalists, the late Messrs. Everett and 

 Whitehead, and Mr. Charles Hose, by the fact that the author 

 has not been able to add a single new species to the avian moun- 

 tain fauna of the island. Dr. Buttikofer comes to the conclusion 

 that both the mammalian and the avian faunas of Borneo are 

 remarkably homogeneous, especially so far as the lowlands and 

 the mountain bases up to an elevation of about 1000 metres are 

 concerned. In vol. ii. No. i of the same serial, Mr. M. C. 

 Piepers defends his theory of the evolution of colour in Lepi- 

 doptera, as explained at the recent Zoological Congress at 

 Cambridge, against the criticisms of Miss Newbiggin and Dr. 

 von Linden. 



In Nature Notes for August the Selborne Society refers to 

 the urgent need of a crusade against pigeon-shooting. 



The M3. of the second volume of the late Dr. Stark's " Birds 

 of South Africa " has been found amongst the papers of the 

 deceased naturalist, who was killed at Ladysmith during the 

 siege. It has been revised for the press by Mr. W, L. Sclater, 

 director of the South African Museum, Cape Town, and will be 

 shortly published by Mr. R. H. Porter. It will form part of 

 Mr. Sclater's series of volumes on the fauna of South Africa. 



The report of the Zoological Garden of Calcutta for the year 

 1898-99, which has recently been received in this country, 

 gives a favourable impression of the present condition and 

 prospects of this establishment, drawn up by Lieut. -Colonel 

 P. A. Buckland, the honorary secretary and treasurer. The 

 superintendent of the Calcutta Garden, Babu R. B. Sanyal, 

 who represented that Institution at the International Congress 

 of Zoology at Cambridge in August 1898, contributes to this 

 report an interesting account of his experiences at the Cambridge 

 meeting, and of his observations on many of the zoological 

 gardens of Europe, which he took the opportunity of visiting on 

 the same occasion. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey {Macacus cynomolgus) 

 from India, presented by Mr. T. Forsyth Forrest ; a Diana 

 Monkey {Cercopithecus diana) from West Africa, presented by 

 Mr. W. Cleaver ; two Greater Vasa Parrots [Corcuopsis vasa) 

 from Madagascar, presented by Mr. G.»Barfoot ; a Silky Cow- 

 bird [Mohthrus bonariensis) from South America, presented by 

 Mr. F. Willes ; seven Algerian Skinks {Eumeces algeriensis), a 

 Spiny-tailed Masligure {Uromastix acantkinurus) horn North 

 Africa, presented by Mr. G. H. Fernan ; a Common Viper 

 ( Fiper berus), British, presented by Mr. Alfred Cooper ; a 

 Green Lizard {Lacerta viridis), a Dohl's Snake {Zamenis dahti), 

 European ; two Smkts {Coluber prasinus) from Upper Burmah, 

 deposited; two Ring-necked Pheasants (Phasianus torguattts). 



