September 28, 1893] 



NA TURE 



o^i 



I barometer and the position of the typhoon each day from 

 October 8th to nth. Th; auihir considjrs that the occurrence 



'of a high barometer cannot be taken as a satisfactory indicati ui 



I of a typhoon, as is sometime; asssrted, and he gives considerable 

 attention to testing the relation which existed between the 

 occurrence of a high barometer and the typhoon which fol- 



ilowed. The first intelligence of the typhoon reached Shanghai 

 on October 8, when a telegram was received from Manila, 



'dated October 7, reporting it to the south-east of Luzon. Mr. 

 Chevalier is of opinion that the typhoon was situated to the 

 north-east, and not to the south-east of Luzon, and he adds 



, that the Bukhara left Shanghai with inaccurate information. 



' The storm apparently had its centre about sixty-live miles to 



• north-east of Appari at 2 p.m. on the 9th, and it must have 



ivelled directly towards the south Cape of Formosa, being 



about 130 miles distant at 9 p.m. At that time the Bokhara was 



outside the Channel, and had not yet entered into the gale. 



] From the quick fall of the barometer and the veering of the 



' wind from north-east to south-west in a few hours, it is evident 

 both that the centre had passed very near the Cape, and that 

 It had recurved towards the north and north-east, instead of 



jcontinuing to the north-westward. The barometer on board 



jthe Bokhara when at its lowest was 29 ■15 inches, where it re- 



Imained for several hours. On the evening of the loth the vessel 

 was quite unmanageable owing to the heavy wind and sea, and 



iwas cast on the reef before midnight. The paper contains much 

 valuable data relating to the violent storms which occur from 



I time to time in the China seas. 



The detection of particular pathogenic bacteria in water in 



the presence of numerous harmless water forms, involves the 



ase of special methods requiring much care and skill in their 



application. Koch (Zeitschrift fiir Hygiene, vol. xiv. 1893) 



recently recommended for the isolation of the cholera organism 



in water the addition of one per cent, of peptone and one per 



cent, of common salt to 200 c.c. of the water under examina- 



lion. The latter ingredient is added on account of Dunham's 



!iscovery that the cholera bacilli multiply very rapidly when 



more salt than usual is added to the culture material. The 



ireated water is then incubated at 37° C. for periods of ten, 



lifteen, and twenty hours, and agar-plates poured at these several 



intervals, whilst a careful microscopic examination is made of 



the surface of the liquid. Any colonies resembling those of 



he cholera organism are isolated from the agar-plates, and are 



■her testei for the indol reaction, as well as for the patho- 



lie action on guinea-pigs. Koch states that by means of this 



; ■-■thod he was able to identify the cholera bacillus in a number 



'f waters submitted to him during the recent cholera epidemic 



Germany. Quite recently another modification has been 



'lished by Arens, " Ueber den Nachweis Weniger Cholera- 



i.jiine in gniszeren Mengen Trinkwassers." (Miinchener med. 



W'ochenschrifl, 1893, No. 10.) The suspected water is first 



rendered distinctly alkaline by the addition of i-r6 c.c. of a 



>-n per cent, solution of caustic potash to 200 c.c. of the 



'iter, so that the latter contains -Oj-'oS per cent, of KOH. 



! Iiis alkalised water then receives pancreas bouillon in the 



lortion of one to nine parts of the water. This bouillon is 



ii;j3sed of broth obtained from the pancreas to which Witte's 



•one is added, and the whole neutralised with carbonate of 



i I until a highly diluted portion yields a faint red colour 



th rosolic acid. The treated samples of water are then 



ubated and examined as described above. Arens claims that 



I leans of this method cholera bacilli can be detected when 



jsent in such small numbers as 2 in 5 c.c. of water. 



Two official maps of the geology of parts of Germany have 

 ibeen recently published; one of them, " Geognostische 

 iUebersichtskarte des Kijnigreichs Wurttemberg," has a scale j 

 NO. 1248, VOL. 48] 



7iiyx.Vu5- 'Ihe strata are delineated with great minuteness, the 

 subdivisions shown by colour and signs being as follows : S 

 Quaternary, 10 Tertiary, 4 Cretaceous, 11 Jurassic, 18 Triassic, 

 4 Permian, I Carboniferous, i Devonian (?), i Archiuan, 6 

 Igneous. The other map, "Geologische Uebersichtskarte von 

 Elsass-Lothringen," by E. W. Benecke, has a scale TnruVTjii- 

 Although on a slightly larger scale, this map shows fewer 

 subdivisions of the sedimentary series than does that of 

 Wiirttemberg ; the crystalline rocks of the Vosges, &c., with 

 their associated serpentines and limestones, are, however, care- 

 fully drawn. The low price at which these maps are sold is note- 

 worthy- — Elsass-Lothringen, i mark ; Wiirttemberg, 2 marks. 



PRorESSOR CltARLES V. KiLEV has reprinted, from the 

 Third Annual Reuori uf the Missouri iiotanical Garden, the 

 results of his observations, which have now extended over a 

 period of twenty years, on the Pollination of Yucca. Every 

 known species of Yuccaii, absolutely dependent, lor its fertilisa- 

 tion, on the visits of a single species of insect, in all cases a 

 species of PromU'a, a genus of small while moths belonging to 

 the Tineina. The pollen cannot reach the stigmatic tube with- 

 out artificial aid. The species which has been chiefly observed 

 is Yucca filarnentosa, which is pollinated by Proiiuba yuccasella. 

 The process is described in detail by which the female moth 

 pierces the ovary, and deposits the egg in close proximity to an 

 ovule. As soon as the ovipositor is withdrawn the moth runs 

 up to the top of the pistil and thrusts the pollen, which she has 

 gathered from other llowers of the species, into the stigmatic 

 opening, and cross-fertilisation is secured. The larva is de- 

 veloped within the ovary, but the number of ovules destroyed in an 

 ovary is never large, and does not practically affect us fertility. 

 Every otherspecies of Yucca has its own special fertilising species 

 oi J-ronuba. Y. filamentosa is also abundantly visited by another 

 moth, very similar in appearance to live Pronuba, the "bogus 

 yucca moth," Frodoxus decipietis, which is apparently perfectly 

 useless, and is not dependent on the fertilisation of the ovules lor 

 its subsistence. The paper is illustrated by ten plates, and con- 

 cludes with a monograph of the three known species of Pronuba 

 and the ten known species of Prodojius, all named by Prol. 

 Riley. 



The decomposition of any form of energy into two factors, 

 one of which is of a constant magnitude, introduces certain 

 simplilicaiious into the theorems of thermodynamics and 

 chemical physics which appear to merit some attention. 

 Herr W. Meyerhoffer, in the Coinples Keudus, points oat that 

 the constant factor in the case of heat is not the entropy, as 

 maiutained by &L Le Chatelier, but the absolute specific Ileal, 

 which has the dimensions of an energy divided by degrees ot 

 temperature. Entropy, on the other hand, is an energy divided 

 by a number representing the number of degrees possessed by the 

 heat at the time of its passage, and which llerr Meyerhoffer 

 proposes to call the number 01 the isothermal. The confusion 

 between entropy and absolute specific heat arises from the fact 

 that the dimensions of temperature are at present unknown. Herr 

 Meyerholi'er proposes to call the two factors of energy capacity 

 and potential respectively. Then every transfer of heat will in- 

 volve a change of two potentials, and llie cruerwu of a rcvcr. 

 siole process will be the inequality of the two potentials. All 

 the cycles invented since Carnot have always had the same 

 function of transforming the variation of one potential into 

 tliat of another of different nature. By means of this division of 

 energy, most of the known stcecniometric laws can be reduced 

 to one, thus : — The smallest particles of matter have, in a com- 

 parable state, the same capacity of energy. By going through 

 the various forms of energy, Regnault's law concerning the 

 specific heats of gases, and the laws of Dulong and Petit, 

 Faraday, EiJtvos, and Dalton may be severally obtained. 



ii 



