488 



NA TURE 



\_March 20, il 



The exhibition of the submarine objects at the Museum of 

 Paris was closed on March 15, but will be opened on a larger 

 scale on the occasion of the session of the Delegues des Societos 

 Savantts, wLich w ill take place as usual in the Easter holidays. 



The number of members of the French Alpine Club is yearly 

 increasing, and the financial position of the Society is very pro- 

 sperous indeed. The general sitting of the Paris section took place 

 on March 10. M. Janssen delivered an address on the sun. 

 The discourse was illustrated by projections exhibiting all the 

 phenomena connected with the eclipse of 18S3, as observed 

 by him on Caroline Island. It is the first time these pictures 

 have been presented to the public, and they have been very 

 successful. 



Amongst the latest publications in the domain of electricity 

 we notice " Das Elektrische Potential," by A. Serpieri; " Die 

 Elektrische Kraftiibertragung," by Jos. Popper; and "Die 

 Atmosphjirische Elecktricitat," by Prof. Palmieri. Hartleben 

 of Vienna is the publisher of all the works mentioned. 



M. Perrier presented on Monday to the Academy of Sciences 

 of Paris six sheets of the map of Tunisia, which the French 

 military geographers are executing on the scale of I : 100,000. 

 The mapping of the whole country from Algeria to the Tripolitan 

 territory will be published in a few weeks. The publication, 

 which will contain twenty-one sheets, will be completed, this 

 year. This great work will have required only four years to 

 accomplish. The maps are lithograi hed, and will be ultimately 

 engraved. 



We have already mentioned a publication issued by the Direc- 

 tion of Schools at Tifli=, in which the teachers of the Caucasus 

 have the opportunity of publishing descriptions of the interesting 

 but little known districts where they are compelled to stay, often 

 deprived of any intercourse with the civilised world. We have 

 now received the third volume of this publication, which contains 

 several valuable papers. The chief of them is the first part of 

 an interesting memoir, by M. Lavroff, on Ossetia and Ossetians, 

 with a map. In this first part the author describes the country, 

 its orography and hydrography, climate, flora, and fauna, leaving 

 the purely ethnographical part for a second memoir. M. 

 Gadovsky contributes valuable notes on the newly-annexed pro- 

 vince of Kars : its geography, population, tenure of land, and the 

 occupations of the inhabitants. The second part of this volume 

 is devoted to the rich folklore of the Cossacks, Tartars, and 

 Circassians, in w hich the ethnographer will find rich materials. 



In the " Untersuchungen aus dem botanischen Institut zu 

 Tiibhigen " F. Schwarz discusses the structure and functions 

 of the root-hairs of flowering plants. He finds that in maize 

 the surface of a hairy rout is 5'S times greater than that of a 

 root rot covered with hairs ; in the pea I2'4 times greater. The 

 intimate contact of the root-hairs with particles of soil is effected 

 by the conversion into mucilage of the outermost layer of the 

 wall of the hair; the inner layer of the membrane is stained blue, 

 the outer layer yellowish brown by zinc chloriodide. The 

 greatest development of root-hairs accompanies the greatest 

 enerijy of growth of the root. A medium degree of moisture is 

 most favourable for their formiti in ; with plants growing in water 

 they are often altogether suppressed. Nutation promotes their 

 production, especially at the point of curvature. Contact with 

 dry solid bodies has no effect on their production. They are 

 always formed in acropetal succession. They have not in most 

 cases the same form in the same species, being considerably 

 affected by conditions of growth . In many plants the root-hairs 

 are branched. 



The annual prize of 25,000 francs, instituted by the King of 

 the Belgians, will for 18S5 be granted to the author of the bcit 

 work on the means of pojularising the study of gei>graphy and 



developing it in the different educational establishments. 



Foreigners may compete equally with Belgians. The works of 



the competitors must be sent to the Minister of the Interior 

 before January i, 18S5. 



We understand that Messrs. Sanderson and Co. are about to 

 issue a small volume on tall-chimney climbing and lightning-rod 

 testing. 



Capt. a. E. Barlow, Commander of the P. and O. steamer 

 Paramatta, writes as follows to the Times : — " An unusual phe- 

 nomenon was observed during the recent voyage of the P. and 

 O. steamer Paramatta to Sydney, New South Wales, which 

 may be of interest to some of your readers. On December 1 1 

 and the following day, about lat. 10° S. and long. 92° E., the 

 surface of the sea was covered with lava and pumice, some being 

 as fine as sawdust and of a yellowish colour, but several patches 

 of large extent were pissed through with masses of pumice from 

 the size of a cocoanut to that of a hogshead ; this extended over 

 5° of latitude, and probably much more of longitude, as the 

 densest patches all ran in an easterly and westerly direction. 

 The largest specimen of pumice which I picked up was about 

 ten inches in diameter, and appeared only to have been a few 

 days in the water, as there was no deposit on it. This would 

 lead to the conclusion that a submarine upheaval must have 

 taken place long after the great ernption of Krakatoa, in the 

 Strait of Sanda, our nearest approach to which was over 800 

 miles. On the homeward voyage on February i the same phe- 

 nomenon was observed, but in a much less degree, in lat. 4' S., 

 long. 88° E., showing that the mass had drifted to the west- 

 north-west about 500 miles in six weeks." 



Under the title of "New Commercial Plants and Drugs, 

 No. 7," Mr. Thos. Christy has recently issued a continuation of 

 his notes on useful plants which come before him in the course 

 of commerce. The demand for economic plants of every descrip- 

 tion has of late years considerably increased amongst planters not 

 only in our own colonies but also in other parts of the world in 

 consequence of the general de»ire for the greater dissemination 

 of staple articles of cultivation that are acknowledged sources of 

 revenue, and also the introduction of new staples where from 

 long cultivation or the ravages of disease the older and better 

 nown plants have ceased to be remunerative. The circulation 

 amongst planters and colonists generally of such books as this is 

 calculated to do a great deal of good even if it were only to let 

 them know of the existence and properties of certain plants, for 

 while there are many that have a knowledge of useful plants, 

 there are also others who are content to go on growing the same 

 crops that they have always been accustomed to, and though we 

 may not expect full details of the uses of the plants enumerated, 

 nor botanical desctiptijuj of the plants them-elves, sufficient is 

 given in all cases to put the reader on the right track for further 

 information. In some of the subjects, however, very voluminous 

 abstracts are given from some of the best journals in which 

 special articles have appeared. It will suffice to say that the 

 present number of " New Commercial Plants and Drugs " con- 

 tains very interesting articles on the Cacao (Theobroma cacao) 

 and its preparation, the Siam benzoin tree, pepper and nutmeg 

 cultivation, Liberian coffee, and numerous other ec momic plants 

 of very varied uses. 



The Eleventh Annual Report of the National Health Society 

 shows that the Society has carried on its work during the past 

 year in a most practical manner. Hundreds of lectures ou 

 san'tary subjects have been delivered, not only all over the poorer 

 parts of London, bat in provincial towns, to large audiences of 

 working men and women, classes of girls, district visitors, and 

 others engaged in work amongst the poor. The Society is much 

 encouraged by the practical results of the lectures on keeping 



