43« 



NATURE 



[May 25, \^)i 



'Iruntivaal. The first experiment, a bull calf, born and 

 reared in Ondcrctepoort, was infested on January 33 

 with ten adult brown ticks, forwarded from Entebbe, 

 Uganda, and received in the Transvaal on January 4. 

 'ihc ten ticks were found attached to the calf the follow- 

 ing day. 'ihc animal died on the twenty-third day after 

 tick infestation, and from the course of the disease and 

 the post-mortem examination, a diagnosis of East Coast 

 fever was concluded. Koch's bodies were found post 

 mortem on microscopical examination of preparations of 

 the lymphatic glands and spleen. The second experiment 

 was carried out in a similar manner. On February 14 

 a calf was infested with ten adult brown ticks of 

 the same batch, obtained from Uganda. On February 15 

 seven of the ticks were found attached. After an incuba- 

 tion period of thirteen days, a typical fever curve ensued. 

 The animal died on the twenty-fourth day. During the 

 course of the disease, Koch's bodies were found in the 

 glands, and Thcileria parva in the red cells of the blood. 

 A diagnosis of liast Coast fever was also concluded from 

 the post-mortem examination in this case. Koch's granules 

 were frequently found post vtortcm in the lymphatic 

 glands and spleen. — S. J. Meltxer : Distribution and 

 action of soluble substances in frogs deprived of their 

 circulatory apparatus. — Dr. F. W. EdridKo-Oreen : The 

 discrimination of colour. If a definite portion of spectrum 

 T)e isolated it will appear monochromatic, the size of the 

 monochromatic region varying with the luminosity and 

 wave-length of the light and the colour perception of the 

 observer. I^ord Rayleigh has expressed the opinion that 

 he can discriminate between the colours in a monochro- 

 matic region even to the extent of distinguishing between 

 the colours of the two D lines. The author does not find 

 this possible when special precautions are taken to have 

 a pure spectrum and to avoid the physiological effect of 

 contrast through varying intensities of the areas to be 

 compared. The monochromatic area may be magnified 

 without altering its monochromatic appearance, the 

 intensity of the light source being increased to compensate 

 for the diminished luminosity. The monochromatic area 

 may also be examined through a double-image prism, or 

 be projected by means of a double-image prism upon a 

 screen, so that the violet side of one area is adjacent to 

 and just touches the red side of the other area. In this 

 way the monochromatic area may be made as large as 

 desired, the intensity of the source of light being increased 

 as required. An arc light gives two very bright areas of 

 colour. This method is the most favourable for the detec- 

 tion of any difference ; the monochromatic areas, however, 

 still remain monochromatic. 



Royal Meteorological Society, May 17. — Dr. H. N. 

 Dickson, president, in the chair. — Dr. H. R. Mill and 

 C. Salter : The frequency and grouping of wet days in 

 London. The purpose of this paper is to place on record 

 certain facts, derived from the long homogenous records 

 of rainfall kept at Camden Square, bearing on a recent 

 scheme for insurance against rain risks. Days with a 

 rainfall exceeding 20 in. only are dealt with, as this is 

 the limit adopted in several of the policies of insurance. 

 The discussion is, of course, strictly applicable to London 

 only, but it will probably apply fairly well to other inland 

 stations in the south-east of England. The authors have 

 examined a number of instances in which an insurance 

 under one or two of the forms of policy offered would have 

 resulted in a claim had a person in London insured everv 

 day for the week commencing that day during the whole 

 period of fifty-two years. The actual compensation yielded 

 by each 1/. invested during each seven-tlay period from 

 1859-1910 would have been as follows : — 



Policy Jan. Feb. Mar.Apr.May June July Au(r. Sept. Oct. Nov. Dec. Year 



A ... 8/8 6/s 6/10 4/1 4/9 1 1/3 10/7 ii/i lo/i 18/10 15/5 ii/t 10/- 

 B ... 9/1 8/6 7/10 7/7 q/i 11/3 11/4 10/1010/- 13/10 12/8 10/8 10/9 



E. Mawley : Report on the phenological observations for 

 1910. The most noteworthy features of the phenological 

 year ending November, iqio. as affecting vejjetation were 

 the continuous and heavy rainfall in February, a sudden 

 change from cold to warm weather in the middle of Mav. 

 the great dryness of September, and the heavy rains arid 

 low night temperatures in November. During the greater, 



NO. 2169, VOL. 86] 



part of the year wild plants came into blossof?' i.,.h;.,H 

 usual time, the departures from the avcragc- 

 at the end of April and the beginning of M.i ..irlj 



spring migrants as the swallow, cuckoo, and ingiiiingal 

 made their appearance at about their usual dates. 1 h« 

 only deficient farm crops were wheat, barley, and peas, 

 On the other hand, the yield of oats, beans, potatc 

 turnips, mangolds, and hay were above the average, an 

 more especially beans, turnips, and hay. 'Fhe crop 

 apples, pears, and plums was much under average, whik 

 all the small fruits, except strawberries, which yielded 

 well, were also rather under average, 



EUI.NUUKOII. 



Royal Society, March 20.— Prof. T. Hudson Beaie, 

 president, in the chair. — Dr. J. R. Mlin* : .Measurement! 

 on the scattering of light by " ground " glass. Certjdfl 

 preliminary experiments on the scattering power of variouc 

 kinds of ground glass were described, as well as the form 

 of apparatus which had been designed ior the purpose 

 the research. — Margaret B. Moir : The magnetic propertM 

 of certain steels at moderate and high temp* r i;iir. .. Tfc( 

 experiments were made in the physical 

 Glasgow University. In every case the ^, 

 rendered neutral at the new temperature previous to carr 

 ing out the tests. It is essential that this point should bt 

 attended to, and much of the previous work 09 magnetii 

 tion at various temperatures left a good deal to be desir 

 in this respect. One result of interest was the discoverj 

 of a transformation point for carbon steel in the neiglv 

 bourhood of 200° C. The changes in susceptibility whicll 

 accompany the transformation arc very distinct in ca 

 iron and high carbon steels, not so marked for medius 

 carbon steel, and imperceptible for soft iron. — Dr. J. A4 

 Qunn : The pharmacological action of harmine. In thil 

 paper the actions of harmine were shown to be qualit 

 tively very similar to those of harmaline, previouslf 

 described by the author 



Paris. 



Academy of Sciences, May 8. — M. Armami uauuer 11 

 the chair. — P. Appell : The linkages expressed by tin 

 non-linear relations between the velocities. — Ch. Ljill«< 

 mand : The survey of the levels of .Alpine valleys, with 

 especial reference to the water-courses. — A. Michel Ltfvy 

 and A. Lacroix : The materials of the rhyolitic ;ir,d 

 trachytic eruptive explosions of the volcano of Slont D*:-. 

 Details and discussion of two complete analyses of the 

 rhyolitic pumice and four of the trachytic pumice. — A. 

 Mttntz and A. Laintf : The phenomena of the purificatioa 

 of sewage by the soil and by bacterial beds. It has beeif; 

 shown in a recent paper by the authors that in bacterit 

 beds the destruction of organic matter by direct combti 

 tion takes place, and that this effect is greater than tl 

 nitrification. A study has now been made of purificati< 

 by soil under ordinary agricultural conditions, and it hs 

 been found that the conditions of purification are different | 

 in the bacterial beds combustion preponderates and nitrif 

 cation is a secondary phenomenon, in soil nitrificatic 

 predominates. The conclusion is drawn that soil is muc 

 superior as a nitrifying medium to bacterial beds. — 3 

 de Forcrand : The hydrates of rubidium and caesiui 

 fluorides. — Paul Sabatier and A. Maiihe : The catalyti^ 

 decomposition of formic acid. From the reactions alreaif 

 known, formic acid might be expected to split up unde 

 the action of catalytic agents in three ways, giving carb 

 dioxide and hydrogen, carbon monoxide and water, 

 formaldehyde, carbon dioxide, and water respectively. Tt 

 change into carbon dioxide and hydr<^en is produced 

 platinum sponge, reduced copf)er, nickel, cadmium, ar 

 the oxides of zinc and tin. The second reaction 

 furnished by titanium dioxide and by the blue oxide 

 tungsten. Many substances, including thorium oxide, gii 

 all three reactions simultaneously. — L. Cailletet 

 origin of the carbon assimilated by plants. The plantr 

 used in these experiments, according to the conditions oi^ 

 illumination, could take their carbon either from atmo* 

 spheric carbon dioxide or from the organic material con-. 

 tained in the soil, or from both at once. — C. Juel : Simpl 

 cubic surfaces. — H, Larose : Trigonometrical df-v.Mopment 

 with non-orthogonal components. — Georges R6mound« 



