78 



NATURE 



[May 27, 1875 



I?er Naturforscher, Feb. 1875. — This valuable publication 

 contains abstracts of many important papers published elsewhere, 

 most of which are noticed separately in Nature ; but there are 

 also numerous original papers. We point out the following : — 

 On the elements of the flora of the Chalk period, by C. v. 

 Ettingshausen. — On the nature of lichens, by P. Magnus. This 

 is an account of the difference of opinion existing amongst the 

 authorities on the subject in question, some of whom do not 

 think lichens uniform organisms, but rather suppose them to 

 consist of a fungus which draws the greatest part of its organic 

 substance from the Algoe (the so-called lichen Gonidia) round 

 which it grows, while others do not agree with this view ; the 

 author, however, tends to the adoption of the idea as a correct 

 one. — On the Biela Comet shooting stars observed by Herr 

 Winnecke at Strasburg on Dec. 3 last. — On the revival of 

 Rotifera, by Mr. Leidy. — On the atmospheric peroxide of hydro- 

 gen, by Herr Houzeau. — On the colour and specific gravity of 

 sea-water ; observations made on board the German Expedition 

 corvette Gazelle on her voyage to the Kerguelen Island, under 

 the superintendence of Herr von Schleinitz. These observations 

 seem to show that the blue colour of sea-water stands in close 

 relation with the quantity of salt the water contains, and that as 

 the salt decreases the colour passes from blue^to blue-green and 

 dark green. There seems to be such regularity in this, that 

 simply according to the specific gravity of the water the shade of 

 colour could be determined which the water must show, and 

 vice versd. The transparency of the water seems also to increase 

 with its quantity of salt ; that of blue water was found to be 47 

 meters, while that of dark green only 2-5 meters. — On the 

 nature and the laws of adhesion, by J, Stefan. — On the assimila- 

 tion of nitric and sulphuric acids by germinating peas, by Herr 

 Kellner. — New researches on some absorption phenomena of 

 field-soils, by Herr Eichhorn. — On the spectra of comets, by 

 H. C. Vogel, with special reference to Coggia's Comet. — On 

 the copulation of spores of Algte, by P. Magnus. — On the diges- 

 tion of albumen, by R. Maly. — On a new method to investigate 

 the nature of electric discharges, by Herr A. M. Meyer. — On a 

 new theory of the sensation of light, by Herr E. Hering. This 

 theory refutes that of Young and Helmholtz, which adopts three 

 simple colours, red, green, and violet, and sometimes requires 

 certain psychic processes for explaining certain facts. Herr 

 Hering tries to do away with these processes in question. — On 

 the new malleable glass, by Herr J. Fahdt. — On the decomposi- 

 tion of preserved wood, by Max Paulet. 



Zeitschrift der Oesterreichischen Gesellschaft fur Meteorologie, 

 Feb. 15. — This number contains an article on the universal 

 meteorograph, by Prof. Van Rysselberghe, of Ostend. The 

 instrument was fully explained by the inventor at a recent meet- 

 ing of the Meteorological Society. 



March i. — The subject of rain and the barometric minimum 

 is here further discussed by Prof. Reye,who finds that his views 

 agree in the main with those of Herr Hann. Both these meteo- 

 rologists recognise the latent heat of vapour as moving force in 

 rotating storms ; this causes the air to ascend and fresh air to be 

 drawn in. According to Herr Hann, the barometer only sinks 

 fast after a large whirl with a strong ascending current has been 

 formed. Prof. Reye agrees with him in thinking that the rota- 

 tory movement contributes to rarefaction in the centre and thus 

 renders possible the occasional long duration of minima. But 

 he differs with him regarding another point. He considers that 

 the ascending central current can only last so long as its tem- 

 perature, derived from condensation, exceeds that of the sur- 

 rounding air, and that this higher temperature must make 

 pressure lower beneath the ascending current than around the 

 cyclone. Dr. Hann, on the contrary, affirms that condensation 

 has little effect on pressure, and that the minima of storm-centres 

 are not caused by rainfall. Mohn's theory of the propagation of 

 storms in the direction of largest rainfall cannot hold good if the 

 latter view be correct. Loomis has shown how American storms 

 generally move towards the area of greatest rainfall. Mohn finds 

 from observations of 210 European stations that moisture is most 

 prevalent on the front side of depressions. Thorn testifies to the 

 enormous rainfall accompanying storms in the Indian Ocean. 

 Prof. Reye calculates that if it were possible for rain to fall to 

 the amount of I mm. at any place without producing any in- 

 draught of air, the barometer would fall f of a millimetre, and 

 generally in that proportion. Now, in hurricanes, such a con- 

 - dition is more nearly approached than in thunderstorms or steady 

 rains. In the vortex, air and vapour rise so rapidly that they 

 cannot part with much heat, and at the same time the inflow of 



the lower strata is retarded and the outflow of the upper strata 

 accelerated by centrifugal force. There still remains, after 

 liberated latent heat has been employed in expansion, a por- 

 tion which has been disregarded, equivalent to the vis viva 

 of the whirling mass and the work of expansion performed in 

 ascending. With all this evidence he maintains his theory. — 

 In the Klei7iere Mittheilungen v/e have the last part of Dr. 

 Ucke's paper on atmospheric oxygen, containing tables which 

 give its variations in quantity at different seasons, with reference 

 to the me.ins of all stations together, and of the stations taken 

 separately. At Seringapatam the difference between summer 

 and winter is least, viz., i per cent. ; London shows 4, Brussels 

 6, Vienna 8, Petersburg 9, Samara 14, and Barnaoul 16 per 

 cent. Pi-oximity of the sea and elevation obviously produce the 

 low figures, and the more easterly a place lies on the continent 

 the greater are the differences between the seasons. 



The Gazzetia Chimica Italiana, fasc i. e ii. 1875, contains 

 the following original papers, besides a great number ot abstracts 

 from other serials : — On two new derivatives of phloretic acid, 

 by W. Koerner and P. Corbetta. These are researches on 

 methyl- and ethyl-phloretic acids and their products of oxida- 

 tion. The authors arrived at the conclusion that phloretic acid 

 can most probably be regarded as phenolisopropionic acid of the 



formula CgH4. OH. CH j COOH'""^^ ^^^ °"2in of the sul- 

 phides and hyposulphides found in natural sulphur waters, by 

 Prof. E. Pollacci. — Researches on some derivatives from natural 

 and artificial thymol, by E. Paterno. The author considers acety lie, 

 methylic, ethylenic, and the sulpho-methylic derivatives of both 

 thymols, and points out their differences. — On paratoluic nitride 

 and some of its derivatives, by E. Paterno and E. Spica. — A 

 note from Dr. M. Fileti, on a glucosate of copper. — Account of 

 experiments made by the same author and E. Paterno, to obtain 

 a carbo-cymenic acid. The experiments made until now with 

 natural thymol and its artificial substitute obtained from cymene, 

 show that both are hydroxyl derivatives of the same cymene, 

 which upon oxidation gives paratoluic acid, and therefore con- 

 tains the propyl and methyl group in the positions I to 4 ; the dif- 

 ference rests therefore only in the position of the hydroxy], and 

 as only the two following oxy- derivatives of parapropylmethyl- 

 benzine 



C3H7 C3H, 



OH 



and I 



^yoH 

 CH3 CH3 



were possible, it remained to be decided which of the two for- 

 mulae applied to natural and which to artificial thymol. The 

 nature of the cresols obtained by Engelhardt and Latschinoff, 

 and by Kekule, by the action of phosphoric anhydride on the 

 isomeric thymols, has rendered it very probable that the first of 

 the above formulae represents the natural thymol, the other the 

 artificial one. The authors made the experiments of converting 

 sulpho-cymenic acid into carbo-cymenic acid, which has the 



( C3H, 

 following formula, CgHg i CH, , and then tried to oxidise the 



( COOH 

 latter, by which they would have finally solved the above ques- 

 tion. They have not quite succeeded yet, although they hope to 

 publish their final results shortly. — On the supposed emission of 

 carbonic acid from the roots of plants, by M. Mercadante and 

 E. Colosi. The authors pretend that no such emission exists. — 

 The remainder of the number consists entirely of summaries 

 from other journals, most of which we have already noticed. 



In the 2"= fascicule of the Bulletin de la Societi d'AntkroJio- 

 legie de Paris for 1874, M. Dareste concludes his reply to M. 

 Broca's theory of the mode of formation of double monsters, 

 considering them under the several types named by Isidore G. 

 Saint- Hilaire, "janiceps, iniopes, synotcs," and " deradelphes." 

 In a later meeting of the Society, M. Broca entered at great 

 length on the consideration of the " Doctrines of Diplogenesis," 

 and endeavoured to show the untenability of the hypothesis 

 which ascribes this abnormality to fusion rather than to excess of 

 development, and an inherent tendency in the embryo to a 

 repetition or doubling of parts. — A letter was read from M. 

 Prunieres, in which he describes the artificial perforations dis- 

 covered by him in human skulls belonging to the period of 

 dolmens. As early as 1868 the writer first, drew attention to 

 the numerous cases in which cranial and other human bones had 



