274 



NA TURE 



[January i8, 1894 



and Art. The books contain some useful hints to intending 

 examinees, and answers to questions that have been set at the 

 Departmental examinations. A number of test-pipers in mathe- 

 matics, arranged by Mr. R. Roberts, has also just been pub- 

 lished by Messrs. Blackie. 



" La Terre avant I'apparition de THomme " (MM. Bailliere 

 et Fils) is a bulky tome by Prof. F. Priem, in Brehm's Merveilles 

 de la Nature series. In it the author recounts the numerous 

 changes through which our globe has passed in geobgical time. 

 He describes the distribution of land and water during the well- 

 marked periods of this world's history, and deals particularly 

 with the fauna and flora of bygone days. In the latter half of 

 the work, the geology of France is dealt with in a very detailed 

 manner. The book is an courant with recent investigations in 

 geology and palaeontology ; it contains 850 figures illustrating 

 fossils, geological sections, picturesque regions and interesting 

 formations, and is worthy of a high place in the fine series to 

 which it belongs. 



During the last few months we have had the pleasure of com- 

 nnenting upon sever il chatty books on natural history matters — 

 books in which instruction is happily combined with interest. 

 Another volume of a similar kind, " Random Recollections of 

 Woodland, Fen, and Hill,"' by Mr. J. W. Tutt (Swan Sonnen- 

 schein and Co.), has recently been published. We recommend 

 the book to the nature-lover and entomologist because it contains a 

 large amount of information brightly put and generally accurate ; 

 and all who can appreciate the beauties of natural creatures 

 and things would do well to read it. 



A VERY important collection of works is being offered for sale 

 by Messrs. W. Wesley and Son. We refer to the Paracelsus 

 Library of Dr. E. Schubert, who died at Frankforton-the Main 

 in 1892. The library contains 194 editions of the writings of 

 Paracelsus. 548 works which partly or chiefly treat of Para- 

 ceLus, description of his times and the places where he worked, 

 publications of his friends and opponents, and a selection of 351 

 works on alchemy. Altogether this unique collection comprises 

 about eleven hundred books, manuscripts, portraits, and tracts, 

 and it is richer in original editions of Paracelsus than that of the 

 British Museum. It is satisfactory to know that no part of the 

 library will be disposed of separately, with the exception of the 

 portion on alchemy. 1 



An investigation of the mechanics of the interaction of 

 ethyl alcohol and hydrogen chloride is communicated from 

 Prof. Lothar Meyer's laboratory to No, 12, 1893, of l^e 

 Zeitschrift fiir physikxlische Cheinie by Mr. Cannell Cain, 

 Solutions of hydrogen chloride of different strengths were ob- 

 tained by leading the dry gas into the dry alcohol, which was 

 coated by a freezing mixture. A definite quantity of such a 

 solution was then sealed up in a small glass tube, and kept for 

 a definite length of time at a constant temperature in a water 

 bath. The composition of the solution before and after the 

 interaction was ascertained by titrating a known amount with 

 dicinormal soda solution. The results show that concentration 

 and time of reaction being the same, the extent of the chemical 

 change increases rapidly with the temperature. Up to 15° 

 there is no appreciable interaction, but in a solution containing 

 100 equivalents of alcohol and 81 of hydrogen chloride at 80° 

 some 15 per cent., and at 99 some 50 percent, of the latter enter 

 into combination in one hour. For a given temperature and 

 concentration the amount of decomposition increases with the 

 time at a rate which gradually diminishes, and finally becomes 

 zero. Temperature and time of reaction being the same, it is 

 also shown that increase in the quantity of alcohol in the above 

 solution, or addition of water or ethyl chloride, retard the rate 

 of change. By experiments with water and ethyl chloride the 

 NO. 1264, VOL. 49I 



author makes clear the reversible character of the action, and 

 next makes observations to ascertain the relative proportions 

 of the substances present when equilibrium is established. In 

 these experiments various solutions of hydrogen chloride in 

 alcohol, alone, and in presence of different amounts of water 

 are employed. Here it is shown that Guldeberg and Waage's 

 law is obeyed, as the product of the active masses of alcohol 

 and hydrogen chloride bears a constant ratio to the product of 

 those of water and ethyl chloride unless in cases where ethyl 

 chloride separates out, and the solutions thus become hetero- 

 geneous. If the alcohol and hydrogen chloride be present in 

 equivalent amounts the results indicate that the equation 

 C2H5OH + HCI + 3C2H5CI + 3II2O approximately represents 

 the condition of things when equilibrium is attained. 



In the review of Mr, Richard Inwards' " Weather Lore," 

 that appeared in these columns on January 4, p. 219, the author's 

 attention was commended to a collection of " wise saws" made 

 for the U.S. Signal Service by Major Danwoody. Mr. Inwards 

 points out to us that his book contains extracts from this 

 collection, and that he acknowledges his obligations to it in the 

 introduction. We regret that this acknowledgment was over- 

 looked by the writer of the notice. 



The additions to the Zoological Society's Gardens during 

 the past week include two Mozambique Monkeys (C^r^/zV/^^j-wj 

 pygerylhrus) from East Africa, presented respectively by Mr. 

 H. P. East and Mrs, Adams ; two Common Marmosets (Hapale 

 jacchits) from South-east Brazil, a Common Hamster [Cricettis 

 fnimentarius) European, presented by Mrs, Brightwen ; two 

 Jackdaws {Corviis moneJida) British, presented by Miss 

 Williams; a Clifford's Snake {Zamenis Cliffordi) from Egypt, 

 presented by Mr, W. L, Tod; a Malaccan Parrakeet {Pahvornis 

 longicaiida) from Malacca, deposited ; a Snow Leopard (Felis 

 jincia) from Lahoul, Punjaub, Himalayas, an Alpine Marmot 

 {Arctoviys marinottd) European, two Hairy Armadillos {Dasyptis 

 villosus), a Black-necked Swan {Cygnus iiigricoUis), two Rufous 

 Tinamous {Rhyncholus 7-ufescens), two Brazilian Caracaras 

 {Polyboi'iis brasiliensis), two Common Teguexins ( Tupinambis 

 teguexin), a Common Boa {Boa constrictor) from South America, 

 a Melodius Jay Thrush {Leucodioptron canontm) from China, 

 purchased; two Lapwings {Vanelltis vulgaris), two Dunlins 

 [Tiittga alpina) British, received in exchange. 



OUR ASTRONOMICAL COLUMN. 



SuNSPOTS AND SoLAR RADIATION. — Spectroscopic observ- 

 ations, the discussion of the frequency of tropica! cyclones, and 

 cyclical variations of barometric pressure, indicate that the 

 greatest amount of heat is received from the sun by the earth 

 during a maximum epoch of solar activity. But, on the other 

 hand, the discussions of s'atistics of air temperature and solar 

 radiation suggest that that the sun's heat is greatest when his 

 surface is least spotted. Some new facts in connection with this 

 paradox are described by M. R. Savelief in the current Coinptes 

 Rendtis, and seem to combat the latter result. He has made a 

 large number of observations with a Crova's actinograph since 

 June 1890, and compared them with the late Dr. Wolf's num- 

 bers showing the relative frequency of solar spots. A few ob- 

 servations are given indicating that the solar constant increases 

 with the increase of solar activity. M. Saveliel has also calcu- 

 lated the mean quantity of heat received on one square centimetre 

 of horizontal surface on the ground during one day, and for an 

 hour of solar radiation. The results obtained by this method, 

 like those deduced from the solar constant, point to the con- 

 clusion that the calorific intensity of solar radiation increases with 

 the activity of the phenomena visible upon the surface of the 

 sun, that is to say, with the increase of solar spottedness. These 

 results are diametrically opposed to those obtained by previous 

 investigators (see Nature, vol. xliii. p. 583), and, if they are 

 confirmed, a real difficulty in the way of explaining the correlation 

 of solar and meteorological phenomena will hive been removed. 



