April 4, 19 18] 



NATURE 



99 



lained confirm those of Bragg and Pierce in the case 

 elements used in common. (2) The atomic 

 lorescent absorption coefficient is proportional approxi- 

 mately to the fourth power of the atomic number of the 

 absorber. (3) The following relation exists between the 

 'omic fluorescent absorption coefficient, atomic number 

 ! the absorber, and the wave-length of the radiation 

 isorbed, /a=CN*A^, where C is a constant over cer- 

 .\\\ ranges, but changes abruptly at critical points. 

 his relation is independent of the scattering co- 

 ficient; it refers oiily to the loss of energy of X-radia- 

 liun by the production of corpuscular radiations and 

 ;ht fluorescent X-radiations that accompany them. 

 14) Calculations based on the above general relation 

 >how that the molecular total absorption coefficients 

 if different substances observed by Auren with radia- 

 in of wave-length 0-35x10-* cm. may be deduced 

 ly approximately from the atomic total absorption 

 ,ucfficients obtained for difi^erent elements with radia- 

 tion of wave-length 0586 x 10-* cm. if the coefficient of 

 scattering be assumed to have a constant value of 02 

 for all elements from hydrogen to bromide for both 

 these radiations. 



Linnean Society, March 2i.^Sir David Prain, presi- 

 dent, in the chair. — Aiiss B. Muriel Bristol : A Malayan 

 form of Chlorococcutn humicola (Naeg.), Rabenh. 

 Cultures were made in October, 1915, from about sixty 

 specimens of soil, the observations now reported being 

 obtained, from Kajang, near Kuala Lumpor, Malay 

 States, after about two years in a closed specimen- 

 tube ; the soil was placed in a mineral-salt solution and 

 allowed to remain under the room-temperature. In 

 June, 1916, growth of the soil-alga began, and its life- 

 history is now set out, tracing it from the vegetative 

 cells, which are solitary or congregated into globular 

 clusters. Later, multiplication by zoogonidia was ob- 

 served, with their fusion forming zygotes, also by 

 aplanospores, but true vegetative division does not take 

 place. The same alga was found in soil-cultures from 

 English localities, in some cases of considerable age. 

 Thus a sample from Rothamsted Experimental Station 

 taken in 1856 yielded the alga, but a sample taken 

 in 1846 did not, so that presumably a period of seventy 

 years marks the extreme limit of revival. 



Zoological Society, March 19.— Pr. A. Smith Wood- 

 ward, vice-president, in the chair.— Miss Maude L. W. 

 Cieghorn : First report on the inheritance of visible and 

 invisible characters in silkworms. 



Mineralogical Society, March 19. --Mr. W. Barlow, 

 president, in the chair. — Prof. E. S. Federov : Graphical 

 operations with four independent variables. .4 propos 

 of Boeke's suggestion of the use of multi-dimensional 

 geometry for such operations, with special reference to 

 the case of the chemical constitution of tourmaline, 

 the author remarks that he had already put forward 

 a similar suggestion, without, however, making use of 

 imaginary dimensions. A system of points is replaced 

 by a system of vectors, and in this way, since each 

 end of a vector has two co-ordinates, a relation between 

 four independent variables may be expressed graphic- 

 ally. Different series of vectors of the first order give 

 rise to vectors of the second order, and they in their 

 turn to vectors of the third order. Certain special 

 cases were discussed. — Prof. R. P. D. Graham : Lattice- 

 like inclusions in calcite from North Burgess, Ontario. 

 The_calcite, which is almost invariably twinned about 

 <'foil2), contains numerous fine needles, arranged 

 parallel to the edges of the rhombohedron c, 

 of a hydrous magnesium silicate, which chem- 

 ical analysis showed to correspond with the 

 formula 5Mg0.6SiO;.4H,0, which is usually 

 a-.>igned to the mineral spadaite. Since the 

 ntedles are only slightly acted on by cold dilute acid, 



NO. 2527, VOL. lOl] 



they remain behind in the form of a lattice on dissolu- 

 tion of the calcite. Other included minerals are 

 pyroxene, quartz, titanite, and pyrites. The source of 

 the solutions which supplied the magnesium silicate 

 was discussed. — Dr. J. W. Evans: Linear rock-dia- 

 grams. The different types of linear or variation 

 diagrams, in which the chemical constituents of 

 different rocks are represented by vertical distances,, 

 were reviewed, and the use of modifications to indicate 

 the probable mineral compositions was proposed. Each 

 rock is represented by two diagrams. In the first or 

 alumina diagram, distances representing the molecular 

 proportions of (i) the potash, (2) the potash and soda,, 

 and (3) the potash, soda, and lime in each rock are 

 measured vertically upwards from the base line, and 

 corresponding points for different rocks are connected 

 by continuous lines. At the same time distances repre- 

 senting (4) the alumina, (5) the iron oxide, and (6) the 

 magnesia are measured on the same lines in the same 

 manner, and are cormected by continuous lines. Not 

 only will this diagram indicate the proportions of the 

 constituents, but also the position of the points on line 

 (4) relative to those on lines (2) and (3) will indicate the 

 probability of the occurrence of minerals dependent on 

 the amount of alumina. If (4) is higher than (3), 

 andalusite, cordierite, or mica may be expected, as well 

 as hypersthene, all the lime being converted into 

 anorthite. If (4) is less than (3), diopside, augite, or 

 the corresponding amphiboles will probably be present, 

 and, if it is less than (2), minerals of the aegirine type 

 may be found. In the second, or silica, diagrams the 

 lowest series of points shows the amount of silica re- 

 quired by the bases of a rock for the formation of 

 leucite, nepheline, anorthite, wollastonite, and olivine, 

 the second series the additional silica necessary to form 

 orthoclase and albite, and the third series the amount 

 required to convert the olivine into hypersthene, while 

 the fourth line repr-^sents the amount of silica actually 

 present. The position of the last relative to the others 

 will throw valuable light on the silicates that may be 

 expected, though allowance must be made for the influ- 

 ence of the bases on one another. For instance, the 

 presence of the constituents of wollastonite will call for 

 a higher silicification of part of the olivine to form a 

 monoclinic pyroxene or amphibole at the expense of the 

 felspars. 



Manchester. 

 Literary and Philosophical Society, March 19. — Mr. W. 

 Thomson, president, in the chair. — Prof. G. Elliot 

 Smith : Race, character, and nationality. The influences 

 of race and heredity, geographical circumstances, and 

 language, though potent in ^^arious directions to affect 

 the character and achievements of individuals and to 

 play a part in the development of the true spirit of 

 nationality in a community, are not the chief factors. 

 The personal experience of each individual, his social 

 environment, and especially the traditions of his com- 

 munity, shape his outlook on life, determine his char- 

 acter, and give specific directions to his inherited apti- 

 tudes. The most powerful forces that mould 

 nationality and weld together a heterogeneous collec- 

 tion of people of varied origin, abilities, and traditions 

 consist of historical circumstances which provide the 

 community with common aims and aspirations, com- 

 mon traditions and social fashions, common trends of 

 thought and modes of behaviour. Such circumstances 

 play a more vital part than mere race or hereditary 

 aptitudes in the development of the spirit of nationality. 



Paris. 



Academy of Sciences, March 18.— M. Paul Painlev^ in 



the chair. — The president announced the death of Lord 



Brassev, correspondant of the .\cademy for the section 



of geograohv and navigation. -P. Termier : Contribu- 



