i82 



NATURE 



[August 19, 1897 



Kinetic energy is the product of Mass into the square of 

 velocity. 



Linear ,, ,, Length into force. 



Surface ,, ,, Surface into surface ten- 



sion. 



Vohime ,, ,, Volume into pressure. 



Heat ,, ,, Heat capacity (entropy) 



into temperature. 



Electrical ,, ,, Electrical capacity into 



potential. 



Chemical ,, ,, "Atomic weight" into 



affinity. 

 In each statement of factors, the ' ' capacity factor " is placed 

 first, and the "intensity factor" second. 



In considering the "capacity factors," it is noticeable that 

 they may be divided into two classes. The two first kinds of 

 energy, kinetic and linear, are independent of the nature of the 

 material which is subject to the energy. A mass of lead offers 

 as much resistance to a given force, or, in other words, possesses 

 as great inertia as an equal mass of hydrogen. A mass of 

 iridium, the densest solid, counterbalances an equal mass of 

 lithium, the lightest known solid. On the other hand, surface 

 energy deals with molecules, and not with masses. So does 

 volume energy. The volume energy of two grammes of 

 hydrogen, contained in a vessel of one litre capacity, is equal to 

 that of thirty-two grammes of oxygen at the same temperature, 

 and contained in a vessel of equal size. Equal masses of tin and 

 lead have not equal capacity for heat ; but 119 grammes of tin 

 has the same capacity as 207 grammes of lead ; that is, equal 

 atomic masses have the same heat capacity. The quantity of 

 electricity conveyed through an electrolyte under equal 

 difference of potential is proportional, not to the mass 

 of the dissolved body, but to its equivalent ; that is, to some 

 simple fraction of its atomic weight. And the capacity 

 factor of chemical energy is the atomic weight of the substance 

 subjected to the energy. We see, therefore, that while mass or 

 inertia are important adjuncts of kinetic and linear energies, all 

 other kinds of energy are connected with atomic weights, either 

 directly or indirectly. . . 



Such considerations draw attention to the fact that quantity 

 of matter (assuming that there exists such a carrier of properties 

 as we term " matter") need not necessarily be measured by its 

 inertia, or by gravitational attraction. In fact the word " mass " 

 has two totally distinct significations. Because we adopt the 

 convention to measure quantity of matter by its mass, the word 

 *' mass " has come to denote "quantity of matter." But it is 

 open to any one to measure a quantity of matter by any other of 

 its energy factors. I may, if I choose, state that those quantities 

 of matter which possess equal capacities for heat are equal ; or 

 that " equal numbers of atoms " represent equal quantities of 

 matter. Indeed, we regard the value of material as due rather 

 to what it can do, than to its mass ; and we buy food, in the 

 main, on an atomic, or perhaps, a molecular basis, according to 

 its content of albumen. And most articles depend for their value 

 on the amount of food required by the producer or the manu- 

 facturer. 



The various forms of energy may therefore be classified as 

 those which can be referred to an "atomic " factor, and those 

 which possess a " mass " factor. The former are in the majority. 

 And the periodic law is the bridge between them ; and yet, an 

 imperfect connection. For the atomic factors, arranged in the 

 order of their masses, display only a partial regularity. It is 

 undoubtedly one of the main problems of physics and chemistry 

 to solve this mystery. What the solution will be is beyond my 

 power of prophecy ; whether it is to be found in the influence of 

 some circumstance on the atomic weights, hitherto regarded as 

 among the most certain "constants of nature " ; or whether it 

 will turn out that mass and gravitational attraction are influenced 

 by temperature, or by electrical charge, I cannot tell. But that 

 some means will ultimately be found of reconciling these apparent 

 discrepancies, I firmly believe. Such a reconciliation is neces- 

 sary, whatever view be taken of the nature of the universe 

 and of its mode of action ; whatever units we may choose to 

 regard as fundamental among those which lie at our disposal. 



In this address I have endeavoured to fulfil my promise to 

 combine a little history, a little actuality, and a little prophecy. 

 The history belongs to the Old World ; I have endeavoured to 

 share passing events with the New ; and I will ask you to join 

 with me in the hope that much of the prophecy may meet with 

 its fulfilment on this side of the ocean. 



NO. 1 45 I, VOL. 56] 



NOTES. 

 We are glad to learn that Lord Armstrong, who has for the 

 past few days been suffering from a slight sunstroke, is now much 

 better. Dr. Gibb, of Newcastle, who was hastily summoned 

 to Bamburgh Castle on Sunday, anticipates that if the progress 

 is maintained his lordship will be quite well again by the end of 

 the week. 



Lieut, de Gerlache's expedition to the Antarctic regions 

 left Antwerp on Monday on board the ^X^zxatx Belgica. 



Pkok. Corfield has been elected an honorary member of 

 the Royal Society of Public Health of Belgium, of which he 

 has been a corresponding member for some years. 



A SPECIAL number of the Rendiconti delta R. Accademia dei 

 Lincei announces the award of the following prizes, besides 

 others for essays of a literary character : — The Royal Prize for 

 physics to Prof. Adolfo Bartoli, of Padua, for his two mono- 

 graphs on the specific heat of water between the temperatures of 

 o" and 35°, and on the heat of the sun, and for other investigations. 

 For the Ministerial Prize for physical and chemical science eight 

 competitors entered, and the judges have awarded a prize of 

 1000 lire to Prof. Carlo Bonacini, of Modena, for his essays on 

 orthochromatic and colour photography, and on the reflection 

 and other properties of Rontgen rays ; also awards of 250 lire 

 each to Prof. Carlo Cattaneo, of Turin, for his notes on the con- 

 ductivity of electrolytes and on the velocity of ions, and to ProL 

 Pietro Bartolotti for chemical investigations relating to the 

 compound Rottlerine and other derivatives. 



Science of August 6 prints a long article, by Mr. Cyrus Adler, 

 on the movement towards an international catalogue of scientific 

 works, and reprints the official reports of the proceedings of the 

 conference held at the Royal Society a year ago. The report 

 which the American delegates. Prof. Simon Newcomb and Dr. 

 John S. Billings, presented to the Secretary of State, was, in ac- 

 cordance with their suggestion, referred to the Secretary of the 

 Smithsonian Institution for his views as to the propriety and 

 feasibility of the work proposed being undertaken by that In- 

 stitution, and as to the probable cost. After considering the 

 matter, Mr. S. P. Langley replied that if the work should be as- 

 signed to the Institution, a grant of not less than ten thousand 

 dollars per annum would be required to carry it out. This- 

 reply and the documents to which it refers were transmitted ta 

 the U.S. Senate and House of Representatives towards the 

 close of last year ; and though no result has yet been reached, it 

 is hoped that Congress will give support to the proposal, so that 

 when the time comes the funds needed for cataloguing the 

 scientific publications of the United States will be granted. 



The meeting of the French Association for the Advancement 

 of Science, which opened at St. Etienne on August 5, was- 

 concluded on Saturday last. At the opening of the meeting,, 

 the President, M. Marey, gave an address on "La methode 

 graphique et les sciences experimentales." The address is 

 printed in the Revue Scientifique for August 7. Next year's- 

 meeting will be at Nantes, while in 1899 the congress will be 

 held at Boulogne, in order that visits may be exchanged with 

 members of the British Association at Dover. 



The St. Petersburg correspondent of the Times reports that 

 at Peterhof on Tuesday morning thirty-six members of the twelfth 

 International Medical Congress, which is to be opened to-day 

 at Moscow, were presented to the Tsar. Each country sending 

 delegates was represented by a small deputation of its more 

 eminent men now present in St. Petersburg, chosen from about 

 6000 altogether who are expected to attend the congress. The 

 British representatives who had the honour of a presentation 



