June 27, 1918] 



NATURE 



^Z^ 



Bull of 1514, giving Portugal the rights to all lands 

 discovered by her in her voyages to the East irrespec- 

 tive of their longitude. The gradual settlement of 

 these questions is traced in later treaties. 



Some valuable medical studies are in course of 

 publication by the Leland Stanford Junior University, 

 California. Of these we have received " Bone and 

 Joint Studies," by Profs. Leonard W. Ely and J. F. 

 Cowan, and "The Pathology of Nephritis," by Prof. 

 W. Ophiils. In the latter it is considered that many 

 forms of inflammation of the kidney are due to bac- 

 terial infections, commonly streptococcal. 



Rocky Mountain spotted fever is a typhus-like 

 disease occurring in limited tracts of country adjacent 

 to the Rocky Mountains. It is conveyed by the bite 

 of a tick {Dermacentor andersoni). Dr. S. B. Wolbach 

 has found present in the endothelium of .the blood- 

 vessels a peculiar bacterium which he surmises is the 

 causative organism of the disease (Journ. Medical 

 Research, vol. xxiv., 1916, p. 121). He has also 

 found the same organism in infected ticks, but not in 

 ticks proved to be non-infective {ib., vol. xxv., 1916, 

 p. 147). Further studies show that the characteristic 

 i lesions of the disease in man are practically restricted 

 ' to the blood-vessels of the skin and genitalia {ib., 

 vol. xxvii., 1918, p. 499). 



In the May issue of the Journal of the Board of 

 Agriculture Mr. R. Robson discusses the probable 

 causes of the poor crops of clover seed obtained in 

 Essex last summer. Popular opinion was inclined to 

 ascribe the seed shortage primarily to the dearth of 

 bees, owing to the ravages of the Isle of Wight 

 disease. This might certainly account for the failure 

 of white clover {Trifolium repens), since there is a 

 general consensus of opinion that the honey-bee is 

 here the chief pollen-carrier. In the case of red clover 

 (Trifolium pratense), however, the predominant role 

 is played by humble-bees, and there is no clear evi- 

 dence that their numbers had been sensibly reduced 

 by the ^disease. An alternative explanation of the 

 small crop is the activity of the very destructive weevil, 

 Apions apricans (Herbs't), which was extremely preva- 

 lent last year. The lirst-cut clover when stacked was 

 infested with maggots resulting from eggs laid by 

 the weevil in the clover flowers, and within a few 

 da\'s the resulting weevils emerged in myriads from 

 the stacks and proceeded to devour the surrounding 

 clover, and then passed on Into the field to lay eggs 

 for the next generation. Every head of clover in 

 I which eggs were laid would produce few or no seeds. 

 [ The weevils move preferably along the ground, and it 

 t was found possible to trap large numbers by means 

 of bands of cloth coated with tar and pitch stretched 

 round the stacks, or by means of a trench containing 

 water and tar. The opinion is expressed that ihe 

 depredations of the weevil were the primary cause of 

 the seed shortage, and farmers are advised to adopt 

 measures to prevent the egress of the second genera- 

 tion of weevils from their stacks of first-cut clover. 



Now that the electro-culture of crops has reached 

 a position of prominence in the public regard, and 

 has even attained the dignity of being invested with 

 a Government Committee, it will probably be a 

 matter of surprise to many that the idea of stimulating 

 plant-growth by means of electricity is more than 

 a hundred and 'fifty years old. An interesting article 

 in the April issue of Science Proi^ress contributed by 

 Messrs. I. J(?>rgensen and VV. Stiles commences with 

 the statement (quoted from Priestley) that the first 

 * experiment on the electrification of growing vege- 

 tables was made by Mr. Malmbray in 1746. The fact 



NO. 2539, VOL. lOl] 



that our present-day knowledge of the subject is but 

 little greater than that of the middle of the eighteenth 

 century is attributed by the authors to the stagnation 

 of the science of the living plant. The vast majority 

 of the researches on electro-culture made since Maim- 

 bray's original experiment are on the same lines as 

 the older ones, and give similar results — i.e. most 

 show the beneficial influence of electrification, whilst a 

 minority show no such improvement. The physio- 

 logical investigations in reference to the subject have' 

 dealt with the process of assimilation, transpiration, 

 respiration, irritability, and protoplasmic movement in 

 plants, but in no case have the experiments been con- 

 ducted in such a way as to furnish any Information 

 as to the Influence of definite electrical conditions on 

 any one of these processes at any definite stage in the 

 history of the plant. The most . Important work on 

 electro-culture is that of Lemstrom, who was the first 

 to treat comparatively large areas of land under crops,; 

 His work made it clear that the overhead electric 

 discharge will affect the life of the plant in all its- 

 phases, and he concluded that the best results are 

 obtained (i) with the network positively charged, 

 (2) by applying the discharge morning and evening, 

 and (3) by having the general conditions favourable 

 -to plant-growth. The authors urge that all the in- 

 vestigators have failed to realise (1) the necessity for 

 measuring the discharge, and (11) that the stimulating 

 eff'ect depending on its Intensity and time of application 

 may differ for different stages of the plant's life, and 

 may appear long after it is applied. 



The Bulletin of the Hawaiian Volcano Observatory 

 for February last is noteworthy for two exceptionally 

 impressive illustrations of the surge of lava in the 

 crater of Halemaumau against central crags rising 

 some 70 ft. above it. 



The glacier that occupied the Irish Sea during the 

 maximum extension of Quaternary ice in the British 

 Isles has played a large part in the distribution of 

 superficial materials, and Mr. J. de W. Hlnch (Irish 

 Naturalist, vol. xxvii., p. 53) gives an excellent 

 review of recent work in the area, and of the evidence 

 which has rendered the hypothesis of an jriferglaclal 

 I submergence both untenable and unnecessary. 



A NUMBER of substances crystallise from solutions, 

 taking up water of ci^rstallisation. This water is 

 absorbed in molecular quantities, and is generally 

 given up again easily with gentle heating. Little is 

 know^n as to how the water is bound in the crystal. 

 Investigations on this question are outlined in the 

 Annalen der Physik for February 15. A number of 

 different forms. of alum, are examined, and cojficlusions 

 are drawn, from spectrum methods, of the structure of 

 I the crystals. , 



I A German firm advertises (Stahl und Eisen, 

 j February 28) a new air-filter, which is said to be 

 ' made entirely of iron. The special advantages claimed 

 ; are :— Great' durability and perfect freedom from fire 

 ; risk ; constant resistance (equivalent to _ from 3 to 

 4 mm. of water) ; no oil, grease, or water is employed, 

 the filter being quite dry. There are no running costs 

 for power or attendance, and no spare parts are neces- 

 sary. Cleaning can be done easily by unskilled work- 

 men. The filter is small in bulk, and can be adapted 

 to the space available. The total capacity of this 

 type delivered or under construction is said to exceed 

 one million cubic metres per hour. 



P. Saxl, in the Gesundheitsingenieur, describes his 

 investigations on the effect of silver in destroying bac- 

 teria in water. It has for a long time been recognised 

 that water that has passed through copper tubes has 



