June 20, 1895] 



NATURE 



•79 



.set of instrnments, and intend to instruct students belonging to 

 the school annexed to the laboratories in their use, and to 

 include, among other studies, a short course of nieteorolc^ as 

 ■applie<l to hygiene. The results of the observations will be 

 regularly published in a special bulletin, with a view to 

 determining more particularly the medico-climatology of that 

 city. 



Miss E. A. Or.merod has sent us a leaflet referring to the 

 Forest V\y (Hippohosca equina, Linn.), a well-known trouble in 

 the New F'orest of I lampshire and its neighbourhood. This fly 

 is to Ix; founil on various kinds of animals, as horses, donkeys, 

 cattle, dogs, and cats, to all of which its presence in the hair is 

 a severe annoyance. jVccording to general telief, the fly feeds 

 by blood-sucking ; it is also said to find nourishment in the 

 perspiration given off by cattle, but further investigation as to 

 how far th is occurs is required. The method adopted to pre- 

 Tenl the attacks is to wipe the horses over with a cloth moistened 

 with paraffin, or with some dilute sanitary solution. 



We have received a copy of Mr. W. E. Plummers Report 

 of the Observations made, under his direction, at the Liverpool 

 Observatory, Birkenhead, during 1894. From obser-ations of 

 twenty-two stars, the latitude of the Observatory, for the mean 

 epoch 18947, ^^'^s found to be 54" 24' 4"'8. A new longi- 

 tude determination has also been made ; exchange of signals 

 with Greenwich Observatory on thirteen nights gave the value 

 I2m. I7'33s. West of Greenwich. The long series of photo- 

 graph records accumulated at the Observator)', has been used by 

 Mr. riummer for the derivation of the diurnal inequality of 

 barometric pressure. The results of his investigation are stated 

 in an appendix to the Report, and are clearly exhibited by 

 means of curves representing the diurnal changes of the 

 barometer in each month, and also for the year. 



O.NE after another, .scientific societies are beginning to organise 

 their literature. Quite recently, under the title " Bibliotheca 

 Geograjihica,*' the first volume of a geographical bibliogiaphy 

 has been published by the Berlin tlesellschaft fiir Erdkunde. 

 The volume contains the titles of all the geographical publica- 

 tions during 1891 and 1892, classified into subjects, and each 

 section arranged alphabetically according to the author's names. 

 In general geography there are diff'erent clas.ses for text-books, 

 historical geography, mathematical and physical geography, 

 biological geography, antl anthropological geography (which 

 covers colonisation and the distribution of disease). The classi- 

 fication adopted for purely geographical i:>apers is very elaborate, 

 and the work done in any region during the years covered by 

 the bibliography can be very easily found. It is proposed to issue 

 annual bibliographies similar to the present volume. The 

 editor of the series is Herr Otto Baschin, and the first volume 

 has been prepared with the assistance of Dr. Ernst Wagner. 



The Belgian Society of Geolog)-, Palaontology and 

 Hydrology, aided by Government and other subsidies, has 

 published the first part of an elaborate rainfall investigation of 

 that country, prepared by A. Lancaster, of the Royal 

 Observatory of Brussels. The author is well known to men of 

 science by various valuable publications, and it was entirely due 

 to his eftorts that the rainfall service in its i)resent complete form 

 was established in the year 1882. The complete publication 

 will consist of two or three volumes, the first of which contains 

 224 octavo pages, accompanied by a map drawn by the 

 Military Cartographical Institute, to the 400,000th of the true 

 >cale. The number of rainfall .stations dealt with is 282, and 

 the monthly sums and means are given for the whole period, 

 together with a series of tables showing the geograi)hical 

 distribution according to catchment basins, and tinted charts 

 showing various annual rainfall zones. The second part will 

 contain various supplementary tables, such .as the distribution of 

 NO. 1338, VOL 52] 



rainfall according to seasons, variability of rainfall, &c. ; the 

 expense of this part is to be defrayed from the proceeds of the 

 sale of the first part, which is issued at cost price. 



From the point of view of stereochemistry, the supposed 

 impossibility of preparing optically active halogen compounds- 

 from the corresponding active hydroxy-acids has been a serious- 

 defect in the strong array of evidence which has com])elled the 

 acceptance of van't Hoff's hypothesis of the a-symmctric carbon 

 atom. This defect has at last been remedied by P. Walden, 

 who describes a series of active halogen substitution products in 

 the current number of the Berichte. Inquiring whether the 

 inactivity of the halogen derivatives prepared by replacement of 

 the hydroxyl group in active compounds by bromine or by 

 chlorine, were due to an inherent quality of the halogen atom, or 

 rather due to the racemisation of the compounds under the 

 conditions hitherto employed in their production, the author 

 undertook the task of examining the methods useil in preparing 

 these compounds. Working on the active hydroxy-acids : 

 malic, tartaric, sarcolactic, and mandelic acids, the substitution 

 of chlorine and bromine for hydroxyl was accomplished by means 

 of phosphorus pentachloride and pentabromide respectively 

 Under the conditions detailed by the author, this substitution 

 was carried out without the racemisation which appears hitherto 

 to have always occurred when these halogen derivatives have 

 been prepared. He has shown that ( i ) dextro-rotatory chlor- 

 or brom-succinic acid may be prepared from the ordinary hevo- 

 rotatory malic acid ; (2) Ijevo-rotatory tartaric acid yields k-cvo- 

 rotatory derivatives of its esters, containing a halogen atom in 

 place of a hydroxyl group, which retain the optical activity due 

 to the presence of the asymmetric carbon atom ; (3) similarly^ 

 dextro-rotatory derivatives of o-chloropropionic acid and a-bromo- 

 propionic acid can be obtained from the tevo- rotatory -sarco- 

 lactic acid ; and (4) laevo-rotatory mandelic acid (from aniyg- 

 dalin) yields dextro-rotatory phenylchloracetic acid and ])henyl- 

 Ijromacetic acid. These active com]X«mds have hitherto only 

 been prepared in the racemic form. Their observed inactivity 

 when so prepared was not due to any accidental limitation of the 

 generality of van't IIolTs theory, but only to the racemisation 

 they had undergone during the process of preparation. It is 

 probably quite generally possible to substitute halogen atoms for 

 hydroxyl groups in combination with active asymmetric carbon 

 atoms without destruction of their optical activity. The activity 

 of the compound depends only on the fact of four dift'erent 

 atoms or atomic groups being connected with one and the same 

 carbon atom, while the amount and direction of the rotation 

 produced is unquestionably related to the specific nature of these 

 atoms and groups. 



The additions to the Zoological Society's Gardens during the 

 past week include two Macaque Monkeys (Macacus cyno- 

 fiio/giis, i f ) from India, presented respectively by Mr. 

 Charles Roberts and -Miss Wieldt ; a Leopard (Fe/ispardtis, 9 )• 

 from India, presented by Mr. Edward Langworthy ; a Common 

 Otter (Ltitra vulgaris, S ), British, presented by Mr. .M. P. 

 Clarke ; a Northern Mocking Bird (Mimiis polyglottus) from 

 North America, presented by Mr. Henry J. Fulljames ; a 

 Vellcjw-throatcd Sparrow (Gyiiiiior/iiiiiisjlavicollis), a Double- 

 banded Pigeon (Trcron hidiiila), two Chinese (Quails {Coliiniix 

 thiiiciisis), two White-breasted Gallinules (Ca///««/<7/A«-H/VK/i;) 

 from India, presented by -Mr. Frank F'inn ; two Weka Rails 

 (Ocyiiroiitus aiislralis) from New Zealand, presented by Mr. 

 Reginald Moorhouse ; two Southern River Hogs (Potoiiiachnrus 

 africantis, i 9 ) from East .\frica, presented by the late Mr. 

 B. W'ard ; a European Pond Tortoise (Eiiiys t-iiropn-a), European, 

 presented by Miss Laura Bedford ; a Sharp-nosed Crocodile 

 (Crocodiliis aciiliis) from Jamaica, presented by Lady Blak'e ; a 

 Black -spotted Teguexin (Tiipiiiatiibis nigro-punclatiis) from 

 South .\merica, deposited ; a Ring-tailed Phalanger (Pseiido- 



