December 15, 1892J 



NATURE 



^S7 



illustrate this communication, were subsequently placed on 

 exhibition in the Spanish section of the Historical Exhibition at 

 Madrid. Her Majesty the Queen of Spain commanded that 

 Mrs. Zelia Nuttall should be presented to her, and expressed 

 much interest in her work. 



No one expects to see the corncrake in Great Britain after the 

 summer months. According to the Llangollen Advertiser, a 

 specimen was caught last Thursday in the neighbourhood of 

 Pentrefelin, Llangollen. Several local naturalists have seen the 

 bird, and agree that it is a corncrake. 



A NEW luminous fungus has been forwarded to Europe from 

 Tahiti. It is said to emit, at night, a light resembling that of 

 the glowworm, which it retains for a period of twenty-four 

 hours after having been gathered, and it is used, by the native 

 women, in bouquets of flowers for personal adornment in the 

 hair and dress. It belongs to the section "dimidiati" of the 

 genus Pleurotus, in which no luminous species has been hitherto 

 known, although there are several in the genus, and has been 

 named by M. Hariot Pleurotus lux. It is believed to grow on 

 the trunks of trees. 



A THEORETICAL investigation of the conditions under which 

 :,ippmann's coloured photographs are produced is given by M. 

 '1. Meslin in the Ann. de Chim. et de Phys. for November. 

 He maintains that the colours produced are complex, and belong 

 to the higher orders of Newton's scale. This is illustrated by 

 the change in colour observed when the thickness of the film 

 increases. When moist air is blown upon it the film swells, 

 and the bright colours give way to others consisting principally 

 of red and green. The impure nature of the spectrum ordinarily 

 obtained would account for its " metallic " appearance. Besides, 

 t here is a blue or greenish-blue region which extends beyond the 

 red end of the spectrum. The composite nature of the colours 

 reflected from the surface of the spectrum photograph may be 

 shown by projecting a similar spectrum upon the film. The 

 colours will then appear very brilliant. But if, for instance, the 

 green is projected upon the red of the film, green is reflected all 

 the same, although less distinctly than before. The same thing 

 happens in other parts of the spectrum. On moving it from the 

 violet towards the red, the violet, arriving at the green portion, 

 is interrupted by a broad band. On further displacement this 

 band, the breadth of which is about equal to the distance between 

 the E and the b lines, moves through the green and yellow and 

 reaches the red. At this moment the blue and violet regions 

 show the greatest brightness. There is only one band observed 

 throughout. This observation is in accordance with the thick- 

 ness attributed to the layers, viz. between 200 and 3SO/i/x. 

 Hence the paths traversed by the light will range from 400/1^11 to 



"joofifj., giving - for none of the colours, ^ - = SoOfi/i for the 

 2 - 2 2 



violet, S^Ofifi for the blue, and 700/i/i for the green. It will be 



still greater, i.e. ^ - for the red, in the infra-red region of the 

 2 2 



spectrum. There we shall have a black band in the red, while 



the blue is at its maximum, owing to the retardation being equal 



to two wave- lengths. Hence the blue region beyond the red 



corresponds to the infra-red region of the incident spectrum, 



which in long exposures is able to produce a photographic effect. 



During the year 1891 about 450 more persons were killed by 

 .vild beasts in India than during the preceding year. The num- 

 l>er in 1890, however, was abnormally low, and the Pioneer 

 Mail calculates that last year's figures were about 250 in excess 

 of the mean. In one district of Bengal — Hazaribagh — no fewer 

 than 205 deaths were due to a single brood of man-eating 

 tigers. The yearly average of persons destroyed by wild beasts 

 in our Eastern dependency is between 2500 and 3000. The 

 NO. 1207, VOL. 47] 



mortality from snake-bite is on a much larger scale. Year by 

 year it varies from something over 21,000 to something over 

 22,000. 



An excellent account of the Experiment Stations established 

 in the United States in the interest of agriculture is given by Mr. 

 R. Warington, F.R.S., in a paper issued by the National 

 Association for the Promotion of Technical and Secondary 

 Education. A fully equipped Experiment Station, he says, is a 

 large and costly piece of machinery, embracing many depart- 

 ments of work. There is one in every State of the Union, and 

 in son>e States there are more than one ; the total number is 

 fifty-four. These Stations are endowed by Congress, £yx)0 a 

 year being paid to the Station or Stations of each State. If the 

 income derived from the State Legislatures, and from other 

 sources, be included, the average income of each Station is nearly 

 ;^4000. In nearly every instance the station is connected with 

 the States Agricultural College, and the Station buildings are in 

 its immediate vicinity. The publications of the Stations are made 

 in the form of periodical bulletins and annual reports ; for the 

 printing of these a special grant is made by the State, and they 

 are distributed by the Federal Government post free. The 

 issues are very large : 60,000 copies of each Station bulletin are 

 printed in Ohio. Any farmer in the State can at his request 

 receive the bulletins regularly without payment. Mr. Warington 

 expresses a hope that our own County Councils may be encouraged 

 to try to do for agriculture in Great Britain what is so ener- 

 getically done for it in America by the various States. 



A SERIES of investigations on soils is in progress at the Mary- 

 land Agricultural Experiment Station, in co-operation with the 

 U.S. Department of Agriculture and the Johns Hopkins Univer- 

 sity, So far the work has been on the physical structure of the 

 soil and its relation to the circulation of soil water, and the 

 physical effect of fertilizers on soils as related to crop production. 

 The surface tension of various solutions was first of all deter- 

 mined. The solutions chosen included common salt, kainit, 

 superphosphate of lime, soil extract, and ammonia. The soil 

 extract was made by shaking up a little soil with just sufficient 

 water to cover it. The water was afterwards filtered off and 

 used for the determination. This operation reduced the surface- 

 tension of water considerably, but the experiments do not appear 

 sufficiently complete to indicate reasons for this. Analyses 

 of the soils are not given. Ammonia and urine lowered the 

 surface-tension of water considerably below that of the soil ex- 

 tract, and still more below that of pure water. Common salt 

 and kainit increase the surface tension of water, and no doubt 

 this is the reason why the application of these substances to the 

 soil tends to keep it moist, whereas the excessive use of nitro- 

 genous manure has the reverse effect. 



The Chamber of Commerce at Reims has published the 

 statistics of the trade in champagne since 1844. In 1844-45 

 the value of the trade was 6,635,000 francs, and in the following 

 year it exceeded seven millions. In 1868-69 't. amounted to 

 nearly sixteen millions, but fell to nine millions in 1870-71, and 

 then rose in 1871-72 to twenty millions. The value in 1872 73 

 was twenty-two millions, and it oscillated between this sum and 

 seventeen millions until 1889-90, when it became twenty-three 

 millions. The figures were 25,776,000 in 1890-91 ; 24,243,996 

 in 1891-92, The number of bottles used in France rose from 

 2,225,000 in 1844-45 to 4,558,000 in 1891-92, while the number 

 exported rose during the same period from 4,380,000 to 

 16,685,900. The year in which most bottles were sent abroad 

 was 1890-91 (nearly Iwenty-two millions). 



Messrs. Swan, Sonnenschein and Co. have issued a 

 translation, by Dr. E, L. Mark, Professor of Anatomy in 

 Harvard University, of the third edition of Dr. Oscar Hertwig's 



