December 28, 191 1] 



NATURE 



291 



lished, specially adapted for the northern hemisphere and 

 tropics, the southern hemisphere and tropics, and the 

 United States. Those who have not yet taken advantage 

 of the valuable aid this pocket-book is when travelling 

 about the world, or even staying at home, should make 

 the experiment now and use one. The writer has for 

 -everal vears always possessed himself of a copy, and while 

 he has had the occasion to employ all the three editions, 

 he has found them most valuable in making the exposures, 

 in recording the data, and in many other useful ways. 



Some novel conclusions in reference to the osmotic 

 pressure of colloids are given by Messrs. Moore, Roaf, and 

 Webster in the October issue of The Biochemical Journal, 

 in a paper on the osmotic pressure of casein in alkaline 

 solutions. It has sometimes been suggested that the 

 osmotic pressure of such substances is due to the presence 

 in them of small quantities of ash. But it is found experi- 

 mentally that alkali moves against the osmotic pressure to 

 the same side of the membrane as the colloid, with which 

 it enters into combination. The authors conclude that the 

 supposed impermeability of the membrane to ions is 

 fictitious, and that its function is merely to hold together 

 the colloidal aggregates by which the crystalloid is 

 attracted and made to traverse the membrane. The thirst 

 of the casein for alkali illustrates the manner in which 

 the colloids of living cells can extract and concentrate 

 crystalloids for their purposes from infinitesimally low 

 amounts in the Huids bathing them, such, for example, 

 as bone formation from the excessively low concentration 

 of calcium ion in the blood, the formation of calcareous 

 and siliceous shells in fresh-water and marine organisms, 

 and manv similar cases. Such concentrations arise from 

 aflfinities of a molecular type between colloids and crystal- 

 loids, which vary from time to time, so causing periods of 

 uptake and deposition in a rhythmic manner. 



The Patent Office Library is well known to all scientific 

 workers in London. The liberal yet careful manner in 

 which additions are made to the library, the wide range 

 of scientific periodicals and journals, and the fact that 

 it is available from lo a.m. to lo p.m., places the library 

 in a unique position in London. The bookshelves are open 

 to the visitors, a much appreciated privilege, but one re- 

 quiring an intimate knowledge of the system of classifica- 

 tion adopted if the time of the visitor and officials is not 

 to be wasted. The new series of subject lists now being 

 issued, while preserving the same form and general 

 arrangement as the former one, is arranged so that the 

 headings contain certain marks indicating the location of 

 classes of books in the library. The most recent subject 

 list in the new series deals with works on peat, destructive 

 distillation, artificial lighting, mineral oils and waxes, gas 

 lighting, and acetylene. It forms a pamphlet of 104 pages, 

 and is obtainable at the Patent Office for 6d. 



The causes of variations in the mineral oils of the 

 United States and other countries have given rise to many 

 investigations and discussions. Not only do these differ- 

 ences exist in oils found in separate regions, but there are 

 extrfme variations in many oils occurring in adjacent 

 localities. It is a plausible hypothesis that the transport of 

 the oil from the lower strata may have been effected, or at 

 least assisted, by capillary action, and during the passage 

 upwards a fractionation of the oil will take place. Day 

 showed that the unsaturated hydrocarbons are less diffusible 

 than the p- Irocarbons, and Gilpin and Cram con- 



firmed ani 1 this view by showing that when 



i to diffuse through tubes packed with 

 msaturated hydrocarbons collect in the 



NO. 2200, VOL. 88] 



earth of lower sections of the tubes, while the paraffins 

 tend to accumulate in the lightest fraction at the top of the 

 tube. Similar experiments have been made by other 

 observers. Additional evidence is given in Bulletin 475 of 

 the United States Geological Survey, on " The Diffusion 

 of Crude Petroleum through Fuller's Earth, with Notes on 

 its Geologic Significance," by J. Elliot Gilpin and Oscar 

 E. Bransky. They show that when mixtures of benzene 

 and a paraffin oil are allowed to diffuse upward through 

 a tube packed with Fuller's earth, the benzene tends to 

 collect in the lower sections, and the paraffin oil in the 

 upper, sections of the tube. Crude petroleum under similar 

 conditions also undergoes a fractionation, and repeated 

 fractionation showed that there is a tendency to the pro- 

 duction of mixtures which will finally pass through the 

 earth unaltered. Fuller's earth tends to retain the un- 

 saturated hydrocarbons and sulphur compounds in 

 petroleum, thus exercising a selective action upon the oil. 



We have received a reprint from the Rivista di Fisica 

 Matematica e Scienze Naturali, Pavia, of a suggestive 

 memoir by Prof. P. Palladino entitled " Les Composes 

 Chimiques dans I'Espace," in which some novel ideas as 

 to the constitution of matter are put forward. The basis 

 of the hypothesis is stated to be essentially " the unity of 

 matter and its possible groupings," and the author believes 

 he has arrived at the form and relative dimensions of the 

 atomic groupings of the unit of matter, or " quantities of 

 combination," of the chemical elements. The memoir is 

 illustrated by seventy-two geometrical figures representing 

 the structure of the atoms and molecules of the principal 

 elements and their compounds, and the text is interspersed 

 wi^h numerous graphic symbols, which act as a convenient 

 notation to represent these various geometrical shapes of 

 the elementary atoms and the molecules of their com- 

 pounds. Definite shape is attributed to the unit of matter, 

 namely, that of a tetrahedron ; thus, for instance, the 

 atoms of oxygen and of phosphorus are supposed to be 

 built up of five tetrahedra, while those of hydrogen are 

 composed of five polytetrahedra, each in turn composed of 

 five smaller tetrahedra. The unit tetrahedron is supposed 

 to be, in turn, composed of a number of electrons. The 

 tetrahedra may be arranged in either a closed or an open 

 manner in many cases, such as in those of oxygen and 

 phosphorus, the difference of structure accounting for the 

 existence of two forms of the same element, the less stable 

 form (such as yellow phosphorus) corresponding to the open 

 arrangement, and the more stable (red phosphorus, for 

 example) to the closed assemblage. Prof. Palladino traces 

 numerous chemical reactions and physical relationships to 

 the forms which he thus attributes to the elementary atoms 

 and the molecules of their compounds, and the whole 

 memoir is both ingenious and highly suggestive. 



A SECOND edition of Dr. Arnold Berliner's "I 

 der Experimentalphysik in elementarer Darstellui 

 been published by Mr. Gustav Fischer, of Jena. The first 

 edition of the work was reviewed in the issue of Natvre 

 for August 4, 1904 (vol. Ixxiv., p. 317). 



Under the title " Abhandlungcn iiber Dialyse (Kolloide)," 

 three of Thomar Graham's papers have been issued as 

 No. 179 of Ostwald's Klassiker der Exacten 

 schaften. The translation has been made by 1 

 who has also added a biography and bibliography, together 

 with a scries of critical notes. 



Erratum. — In i\v- suniin.-iry <>f Pr. Iiitton's Cantor 

 lectures on " Rock Crystal," giv^n in Nature of 

 December 21, a line of type was unfortunatelf omitted. 



