July 26, 1894J 



NA TURE 



305 



or shorter duration, and disinfection was carried out by airing 

 with fire and by medicated fumigation. Nurses on the termina- 

 tion of a case were subject to twenty-eight days' seclusion, and 

 visitors were forbidden the house of sickness." We of to-day 

 could do worse than act upon much of the advice here given. 



In the report of the Puffin Island Biological Station, just 

 received, we find a history of the station since its vacation by 

 the Liverpool Biological Society for their new home at Port 

 Erin. The laboratory was taken over in 1892 by a number of 

 members of the staff of University College, Bangor, and other 

 residents in the neighbourhood ; and a committee of manage- 

 ment was formed, with Mr. P. J. White, who also edits the 

 report, as director of the station. The contributors to the pre- 

 sent report of thirty-two pages deal briefly with special points 

 of interest in the terrestrial fauna and flora and the archreology 

 of the island, and the director offers some suggestions in re- 

 gard to the improvement of the sea-fisheries (shell-fish) of the 

 district. 



The Comfte Rendu of the fifth session of the International 

 Geological Congress, held at W'ashinglon in 1S91, has just ap- 

 peared. The general arrangement of the book closely follows 

 that of the report of the London Congress (1S8S), but it is 

 printed on larger paper. The formal reports of discussions, &c. , 

 are printed in French, but these occupy only a small portion of 

 the book ; the greater part consists of descriptive papers and of 

 fuller reports of some discussions, mainly in English. The de- 

 scription, by C. R. van Hise, of the pre-Cambrian rocks of the 

 Lake Superior region, and the geological guide-book to the 

 Rocky Mountain Excursion, edited by S. F. Emmons, are 

 interesting portions of the report. Some notes and sketches 

 by "visiting geologists" — Prof. T. McK. Hughes and Dr. Fr. 

 I'lech — are appended. We may also here note that Dr. F. 

 " .ihnschaffe has published detailed descriptions of the Western 

 tricts in Natiiriuissenschafllicke WocJunschrift. The Rocky 

 imtain Guide-book is by numerous contributors, and we hsve 

 L-ived a separate copy of that part relating to the Yellowstone 

 r.irk, by A. Hague. 



We have received part i. of the twelfth annual report of the 

 Fishery Board for Scotland, being for the year 1S93. Follow- 

 ing the practice of previous years, the report will be issued in 

 three parts. The third part deals with the scientific investiga- 

 tions conducted under the direction of the Board, and in it the 

 hatchery established at Dunbar for the propagation of marine 

 food-fishes will be described. We learn from the present part 

 that the establishment consists of a small tidal pond, in which a 

 limited number of spawning fishes may be collected and pre- 

 served ; a large concrete spawning tank, in which the fishes at 

 maturity are placed ; a chamber for the automatic collection of 

 the fish eggs, and for the filtration of the water ; a hatching 

 room, in which the special hatching apparatus is fitted up; to- 

 gether with the necessary pumping apparatus. The whole of 

 the expenditure, amounting to about ^1600, has been met from 

 the ordinary vote for scientific investigations. So far, the 

 operations have been limited by the want of a sufficiently 

 capacious sea-water enclosure. Nevertheless, over 25,000,000 

 eggs of the plaice have been hatched in the establishment, and 

 arrangements are in progress with the view of obtaining a 

 supply of adult turbot and soles, so as to admit of these fishes 

 being propagated on a large scale, and the fry placed on the 

 fishing grounds. The opinion is expressed that when large 

 sea-water ponds or enclosures are added, it will be possible to 

 retain the young flat fish until they have assumed the habits of 

 the adults, and thus greatly increase the usefulness of the 

 establishment to the fishing industry. 



A REPORT on the cultivable land on Kilimanjaro, with special 

 regard to its climate and healthfulness, is published by Dr. 

 XO. I 291, VOL. 50] 



Brehme in the last number of the Mittheiluiigen aus Dcutschen 

 Schutzgebieten. The fertile land may be taken as the zone 

 between 3700. and 7000 feet of elevation ; this zone, strictly 

 speaking, measures only 500 square miles, but several thousand 

 square miles of the neighbouring country may be included as fit 

 for settlement. The soil is the result of the weathering of 

 volcanic rocks mixed with the humus formed by decaying 

 vegetation ; it is from I to 3 metres thick on the lower slopes, 

 and of great natural fertility. The water supply is good, from 

 melting snow, as well as from the discharge of the clouds which 

 usually hang over the upper part of the mountain. Rains or 

 wet mists occur frequently at all times of the year. The health- 

 fulness of the slopes watered by rapid streams is in contrast with 

 the fever-haunted marshes of the plain at the base of the 

 mountain, where the slope of the land is insufficient for natural 

 drainage. One very important circumstance is that the water 

 of the mountain streams may be drunk unboiled without any 

 risk. At the station of Marangu (1430 metres), meteorological 

 observations, taken from October 1S92 to December 1893, the 

 highest monthly mean temperature at 7 a.m. was I7°'9 C. in 

 December 1892, and the lowest 13° C. in August 1893. The 

 mountain is exposed to the trade winds, the south-east trade 

 blowing from April to October, and the north-east from the end 

 of October to March ; but the local winds are modified by a 

 general up-hill wind during the day-time, and a down-hill wind 

 at night. The illnesses most common on the cultivable zone of 

 the mountain are much more frequently due to cold than to 

 malaria. In addition to the banana, sorghum, and maize, all 

 European cereals and vegetables grow readily. There seems 

 to be no reason v/hy the experiment of settling European 

 farmers on the temperate uplands of the mountain should be 

 unsuccessful if fairly tried. 



In the last number of the Scottish Geographical Magazine, 

 Prof. Otto Pettersson continues his memoir on recent 

 Swedish hydrographic research in the Baltic and North Seas. 

 In this instalment, which is profusely illustrated with coloured 

 charts and sections, he shows how the observations have thrown 

 new light on the Baltic Current in the Skagerack and North 

 Sea. The outflowing and inflowing currents which traverse 

 the Skagerack can readily be distinguished by the different 

 salinity of the water, the inflowing current containing more than 

 3"2 per cent, and the outflowing less than 3'o per cent, of salt. 

 In winter, when the outflowing current, or Baltic Stream, is 

 reduced to its minimum by the freezing of the rivers, it shrinks 

 to the dimensions of a narrow current along the coa«t, the 

 Skagerack resembling a whirlpool with still water in the middle, 

 and the moving water flowing along the coasts. The water is 

 everywhere warmerthan the air, but most so in the centre. Thus, 

 while the air at or below 0° C. is in contact with water of nearly 

 the same temperature off the Swedish coast, in the centre of the 

 Skagerack it rests on water the surftce temperature of which 

 may be as much as 5° ; thus a central mass of relatively warm 

 air is produced, surrounded by concentric Layers which are colder 

 and colder. This not only affects the climate of the Swedish 

 coast, but is favourable to the formation or attraction of cyclones. 

 In spring the cold Baltic Stream overspreads the warm central 

 waters of the Skagerack with a fresher and colder layer, destroy- 

 ing the conditions favouring the formation or pass.ige of cyclones, 

 and thus produces the typical dry and cold spring weather which 

 prevails in Sweden. 



In a letter to the Electrician, Prof. Elihu Thomson mentions 

 a curious and rather amusing illustration of the principle upon 

 which the instrument for detecting the presence of electric 

 oscillations, devised by Prof. Oliver Lodge, and called by him 

 the " coherer," is based, which came under his notice lately. 

 It will be remembered that the "coherer" depends on its 



