498 



NATURE 



[June 17, 1920 



death of Sir John Murray in 1915 has been controlled by 

 Dr. H. Bradley and Messrs. W. A. Craigie and C. T. 

 Ohiions. Nine of the ten volumes are complete, and 

 as steady progress in the tenth volume is being made 

 we may soon look forward to the completion of this 

 monumental work. 



; 1 In the Annual Report of the Director of the Field 

 Museum of Natural History, Chicago, for 1919, 

 perhaps the most novel pages are those dealing with 

 the, work of the botanical laboratories established by 

 Mrs. Stanley Field. Their main object is to make 

 reproductions of living plants for exhibition in the 

 museum. To accomplish this the plants are studied 

 in the field, wherever they are best to be seen. Thus 

 the first four and a half months of the year were 

 spent irt Florida, at a station of the U.S. Department 

 of Agriculture, to secure studies and material for 

 such'plaflts as the coconut palm, the banana, the 

 pineapple, and the Florida cycad. The most perish- 

 able parts were cast and coloured, and plaster 

 moulds were made of other parts, formalin material 

 packed and sent to the museum, and photographs, 

 colour sketches, and detail studies secured for use 

 after return. Reproductions were made of many 

 other plants cultivated in the garden of the station. 

 A set of tomatoes attacked by various fungi, then 

 under investigation at the station, was reproduced, 

 and pure cultures of the fungi were obtained \yith the 

 view of making an enlarged model of each fungus 

 for exhibition alongside the infected fruit. 



' Few works of the same size have had so wide an 

 influence on geological thought as R. Liesegang's 

 "Geologische Diffusionen," published in 1913. Ap- 

 plications of the author's views on zonal deposition 

 are to be found, with excellent illustrations, in Pro- 

 fessional Papers 107 (p. 156) and 104 (p. 45) of the 

 U.S. Geological Survey. In the former case banded 

 jasper-rock is considered ; in the latter, the very 

 common occurrence of bands of iron hydroxide. 

 Messrs. Bastin and Laney, in Paper 104, have made 

 useful experiments with interfusing solutions of 

 ferrous sulphate and sodium hydroxide. 



A COLOURED geological map of Western Australia, 

 called a sketch-map, but none the less valuable to 

 libraries, accompanies the Annual Progress Report 

 of the Geological Survey of that State for 1918 (pub- 

 lished 1919). Its scale, I in. to 50 miles, or about 

 I : 3,000,000, is large enough to enable us to appre- 

 ciate the immense extent of Nullagine (Late Pre- 

 Cambrian?) beds in the north-west, with their auri- 

 ferous conglomerates ; the Jurassic fringe on the west 

 coast ; and the Cretaceous overflow on Palaeozoic strata 

 in the south-east. An interesting case of serviceable 

 limestone formed by capillary action in sand-dunes is 

 described on p. 14 of the report. 



A SUMMARY of the weather for the spring season, 

 comprised by the thirteen weeks ending May 29, is 

 given in the Weekly Weather Report issued by the 

 Meteorological Offlce. Mean air temperature for the 

 period was above the average in all districts of the 

 NO. 2642, VOL. 105] 



British Isles, the largest excess being 3-2° F. in 

 England E. and 2-9° F. in England S.E. In Ireland 

 the excess was not more than ^° F., and in Scotland 

 it was only about 1°. At the close of the season the 

 sheltered thermometer exceeded 80° F. in most of the 

 English districts. The day-degrees above 42° F, were 

 largely in excess of the normal over the whole king- 

 dom, especially in England E. and in the English 

 Channel, whilst the day-degrees below 42° F. were 

 largely deficient everywhere, especially in the Midland 

 Counties and in England E. and N.E. Rainfall was; 

 everywhere in excess of the normal, the greatest excess 

 being 5-67 in. in England N.W. In the English 

 Channel the excess was only 0-59 in., and in England 

 S.E. and E. 0-63 in. and 0-67 in. respectively. The 

 duration of bright sunshine was normal in Scotland N ., 

 but deficient in all other parts of the British Isles. In 

 Scotland W. the deficiency was 109 hours, and in 

 England N.W. and Ireland S. 91 hours. 



The second part of the current volume of the 

 Proceedings of the Royal Irish Academy consists of 

 a paper by the late Prof. J. A. McClelland and Mr. 

 A. Gilmour on the electric charge on rain. The 

 observations were made in a small quadrangle at 

 the back of University College, Dublin, between 

 January i and August 31 last year. The results 

 for non-thunderstorm rain are that 73 per cent, of it 

 was charged positively, and 84 per cent, of the elec- 

 tricity brought down was positive. The average 

 charges brought down by the rain were 0-21 electrostatic 

 unit positive and 008 negative per c.c. of water. 

 The average vertical currents were i-6x 10-'* amperes 

 per sq. cm. positive and o-5Xio-" negative. Drops 

 below 008 X 10-' c.c. were always negatively charged, 

 but there appeared to be no relation between the size 

 of the drop and the magnitude of its charge. Thunder- 

 storm rain was more highly charged than ordinary 

 rain and about equally positive and negative. Snow 

 was more often negative than positive, small hail 

 always negative, and large hail always positive, the 

 charges per c.c. exceeding those on ordinary rain 

 and often those on thunderstorm rain. 



In Publication No. 298 of the Carnegie Institution 

 of Washington (1919) Messrs. E. L. Nichols and 

 H, L. Howes, with the collaboration of Messrs. E. 

 Merritt and D. T. Wilber and Miss F. G. Wick, give 

 the results of a very exhaustive investigation of the 

 fluorescence and absorption spectra of uranyl salts. 

 The authors have examined a large number of simple 

 and double salts, the influence of water of crystal- 

 lisation and of crystalline form, and the polarised 

 fluorescence of crystals at prdinary temperatures and 

 at the temperature of liquid air. The results obtained 

 at low temperatures are of particular interest, for 

 under these conditions both the absorption and 

 fluorescence bands, which at ordinary temperatures 

 are so diffuse that it is difficult even to locate the 

 positions of the maxima with great precision, are 

 resolved into a number of comparatively sharp com- 

 ponents the homologous members of which can be 

 arranged in series having constant wave-number 



