446 



NATURE 



{Sept. 4, 1879 



contact with the surface of its liquid when that surface is convex 

 or concave is greater or less respectively than when flat. It rests 

 , upon the assumption that evaporation is not purely superficial but 

 that molecules are emitted from a certain depth beneath the 

 surface of a liquid. From this it follows that the chances of 

 escape of a molecule from a given depth below a convex surface 

 are greater, and from a concave less than from a flat one. Taking 

 the depth from which emission takes place at very small com- 

 pared with the radii of curvature of the surface, the author has 

 deduced the same formula for the increase or diminution of 

 tension as Sir W. Thomson deduced from capillary phenomena. 

 Etherspheres as a Vera Causa of Natural Philosophy, by Rev. 

 S. Earnshaw, M.A. — The author, assuming an admitted paral- 

 lelism between the phenomena of light and heat, proceeds by 

 means of three hitherto overlooked propositions in natural 

 philosophy to establish the universal existence of what he has 

 denominated etherspheres, the third of his propositions being — 

 "Every atom of matter in the universe is surrounded by an 

 ethersphere of its own." The following is the system of nature 

 which he finds sufficient for his purpose : — ■ 



1. In nature there are two distinct substances, matter and 

 ether, neither of which has any power to attract or repel the 

 other. 



2. Matter consists of atoms which attract each other with 

 forces varying according to the Newtonian law (distance)-^. 



3. The atoms of bodies of the same kind are alike in all 

 respects ; atoms of bodies of difierent kinds differ from each 

 other in size, and possibly also in other respects, such as 

 shape, &c. 



4. Atoms, whether of matter or of ether, are incapable of 

 experiencing any change of figure or dimensions ; and they are 

 all assumed to be of such geometrical forms as cannot fill space. 



5. From the phenomena of light it has been inferred that 

 atoms of ether repel each other with a force varying as (dis- 

 tance)-4. 



6. Every atom of matter is impervious to ether, and acts on 

 ether in no other way than by pressure of contact. 



7. A portion of space filled with matter is necessarily void of 

 ether ; and all space void of matter is pervaded by ether. 



8. The enormous velocity of light in free space has led to the 

 opinion that very great must be the repuLive power of ether on 

 ether ; and it seems to follow from this that an ether atom will 

 experience great difficulty in moving from one part of the ethereal 

 medium to another. Except as waves and currents, ether motion 

 will be under great restraints, and especially shall we fee this 

 when we also remember the high power (viz., the fourth) of its 

 inverse law of force. 



9. In free space light is believed to be transmitted with the 

 same velocity in every direction, and from this we infer that the 

 atoms of ether are all spherical in form. 



The following is the author's definition of an ethersphere : — 



All space not filled by matter is pervaded by ether, so that 

 every atom of matter is surrounded by ether, but this is not what 

 is included in the word "ethersphere." The author shows that 

 if any portion of space be rendered void of ether from any cause 

 whatever, that space has become void of the repulsive fcrccs 

 which were centred within it, and that, consequently, when these 

 forces are taken away the medium outside the space will draw 

 closer towards that space ; and if the space be occupied by an 

 atom of matter, the density of the surrounding ether will be 

 greater than before, and the ether, being in contact %vith the 

 atom at its surface, will press upon if. This excess of ether about 

 the vacant space above its original quantity constitutes the ether- 

 sphere ; and though this gathering together of ether about the 

 space now occupied by the atom is a consequence of the presence 

 of the atom, it is in no way owing to its action on the ethereal 

 medium. 



The author then argues that if every material atom, so must 

 every compound system of atoms, i.e., every material body, 

 whether gaseous, liquid, or solid, have an ethersphere, which 

 not only surrounds the whole body, but also penetrates the inter- 

 stitial spaces of the body which lie between its atoms. 



By means of these etherspheres the author believes the pheno- 

 mena of heat may be satisfactorily accounted for, on the supposi- 

 tion that the ethereal medium is the medium of heat as well as 

 of light. They are shown in the original memoir itself to have 

 a remarkable bearing also on the phenomena of magnetism, 

 electricity, galvanism, and the various sciences connected with 

 the agency of imponderables. He therefore concludes that 

 etherspheres constitute a vera causa the exittence of which in 



nature is as certain as is that of the ethereal medium itself, about 

 which no philosopher expresses doubt in the present day. 



On the Fundamental Principles of the Algebra of Lode, by 

 Alexander Macfarlane, M.A., D.Sc. — In a work recently pub- 

 lished, entitled "The Algebra of Logic," the author has investi- 

 gated anew the foundations of that branch of mathematical analysis 

 which was originated by Boole in his cele!)rated treatise on 

 "The Laws of Thought." In making this inquiry the author 

 has studied the contributions to the subject made by Harley, 

 Venn, Jevons, and others. 



The difficulty and apparent irrationality of Boole's calculus is 

 due to the fact that it is founded on the old and inadequate 

 theory of the operation of the mind in reasoning about quality. 

 That theory supposes that the mind, in forming a compound 

 conception out of two simple conceptions, necesfarily considers 

 the second of these as limited by, and in a measure dependent 

 upon, the first ; in the theory which the author advances it i.s 

 maintained that the mind may, on the other hand, form com- 

 pound conceptions in v\hich the second element is entirely de- 

 pendent on the first ; and, on the other hand, compound 

 conceptions, in which the two elements are mutually indepen- 

 dent. 



The author considers that the fundamental notion in this 

 branch of analysis is that of a collection of homogeneous objecSs 

 having differentiating characters. The collection of objects, so 

 far forth as they are homogeneous, may be denoted by u (as they 

 form the universe considered in the particular investigation) ; a 

 differentiating character may be denoted by a small letter, as x. 

 The symbol x applies to, and is entirely dependent upon, ;/. 

 The arithmetical value of « is the number of the objects con- 

 sidered, and may be singular, plural, or infinitely great. The 

 arithmetical value of x is the ratio of the number of the object.' 

 which have the character x to the whole number of objects con- 

 sidered. The author then explains the meaning of the letters and 

 symbols in this system of logic. 



On Synchronism of Mean Temperature and Rainfall in the 

 Climate of London, by II. Courtenay Fox, M.R.C.S. — The object 

 of the paper is by the examination of a long series of facts to 

 ascertain whetlier there be any law which regulates the (7irir«?-;-«;<:t' 

 at the same time of extremes of temperature and rainfall, so far 

 as we can ascertain it in the English climate. 



The facts used are the rainfall and mean temperature as 

 for the Royal Observatory in each month and season for 

 66 67 years. The mean temperature from 1813 to 1840 is that 

 computed by Mr. James Glaisher, F.R.S., {vide Philosophical 

 Transactions, 1850, part 7) ; and from 1841 to the present time, 

 it is from direct observation. The rainfall from 1830 to 1840 is 

 derived from sundry observations about London collated by Mr. 

 George Dines, and from 1841 to the present time it also is from 

 direct observation at the Greenwich Observatory. 



The author has constructed tablesyc'r each month, in which the 

 sixty-seven (or sixty-six) years are arranged in the order of the 

 mean temperature of that month, beginning with the coldest and 

 ending with the warmest, and also arranged in like manner in 

 the order of their amount of rain. The sixty-seven years are 

 then divided, as nearly as can be, into five equal sections, of 

 which the middle section is termed average years ; the division 

 on each side of the average are termed cold and warm, dry and 

 rainy, respectively ; while the extreme sections are qualified by 

 the word very, being called very cold, very warm, very dry, and 

 very rainy, respectively. We have thus a pretty fair division of 

 the series of years in both these characters. What has been 

 done for each month has been also done on exactly similar 

 principles for each season and for the whole year. The reiults- 

 found were ; — 



1. In the winter months, cold tends to be synchronous with 

 dryness, warmth with large rainfall. 



2. In the summer months, cold tends to be accom.panied by 

 much rain, warmtli by dryness. 



3. Rainy years tend to be either very cold or very warm, 

 whiht years of drought tend to assume an average temperature. 



Experiments on the Influence of the Angle of the Lip of Pain 

 Gauges on the Quantity of Water Collected, by Baldu in Latham, 

 C.E., M. Inst. C.E., F.G.S., F.M.S.— The author having ob- 

 served that, in the ordinary pattern of the Glaisher gauge, in 

 high winds the rain was often driven up the sloping lip and into 

 the gauge, thought that if the rim of the gauge were made very 

 acute, having a sharp knife edge and equal angles botli inside 

 and outside the gauge, any rain which might strike upon the 

 outer angle on one side of the gauge might be thrown into the 



