45o 



NA TURE 



[March 12, 1903 



a brief classification of the subjects included under the 

 general term of anthropology, Dr. Haddon said his reason 

 for touching on the subject at all was to suggest a general 

 survey in the hope that fellow-students may carefully con- 

 sider the lines upon which future research may be under- 

 taken with profit, as there are times and occasions when one 

 branch of inquiry is more immediately desirable than 

 another. A few remarks were made on certain aspects of 

 anthropological research, and various lines for future in- 

 vestigation were indicated. 



A claim was made that the ethnological material now 

 being collected from all over the earth is an indispensable 

 contribution to the science of history. It is a truism that 

 history repeats itself, and historians were invited to consult 

 the modern instances that are accumulating, as they will 

 find many suggestions that will serve to throw light upon 

 past events, which otherwise might remain obscure. It is 

 hardly an exaggeration to say that new life has been given 

 to classical studies by the introduction into the universities 

 of original archaeological investigations, comparative 

 archaeology, ethnology and folklore. Allusion was made 

 to the recent signs of an interest in ethnological inquiry by 

 various Governments of the British Empire. " Is it too 

 much to hope," it was asked, " that at last it is being 

 recognised that a full knowledge of local conditions and a 

 sympathetic treatment of native prejudices would materially 

 lighten the burden of government by preventing many mis- 

 understandings, and by securing greater efficiency would 

 make for economy? ■ . • We have not yet exhausted other 

 methods of advancing anthropology, we have scarcely yet 

 endeavoured to educate the masses or to interest individuals 

 who have time or money at their disposal. Few people 

 have any idea of the great wealth of human interest there 

 is buried in the data in the journals of our societies, or 

 locked up in the cases and drawers of our museums. It 

 is this practically unexploited wealth of interest and inform- 

 ation that we should endeavour to disseminate. The apathy 

 of the public to our science probably is largely due to its 

 students. ... I have indicated some of the lines upon 

 which our Cinderella science is advancing, but before I 

 finally vacate the honourable position to which you have 

 called me, I must return once again to its most pressing 

 need. 



" Students at home spend laborious hours in reading, tran- 

 scribing or collating the records of travellers, and in en- 

 deavouring to make them yield their secrets. The safety 

 of the student usually depends upon the bulk of his material, 

 but when one considers the sources of his information, one 

 is sometimes appalled at the dangers he runs. The data that 

 are available have been collected in varied circumstances 

 by men of every degree of fitness and reliability. There 

 are but two remedies for this state of affairs — trained 

 observers and fresh investigations in the field. Fortunately, 

 we are now in a position to. say that means do exist for the 

 training of field-anthropologists. Those who have had 

 practical experience in Oceania, or who followed the liter- 

 ature of that region, will fully acknowledge the urgent 

 need there is for immediate field-work. But the same press- 

 ing necessity is manifest in every quarter. Nor is it a call 

 that we can neglect with impunity and postpone until a more 

 convenient season. Each year sees a decrease in the lore 

 we might have garnered, and this diminution of opportunity 

 is taking place with accelerating speed. Oh ! if we could 

 only agree to postpone all work which can wait, and spend 

 the whole of our energies in a comprehensive and organised 

 campaign to save for posterity that information which we 

 alone can collect." 



I 



ELECTRICITY AND MATTER.' 



FHE subject I have chosen is an enormous one, but it is 

 x one of exceptional interest at the present time. It is 

 one of general interest as well as of scientific interest to 

 students of physics. The fundamental properties of matter 

 are now coming to be understood in a way in which they 

 have never been understood before. What are these funda- 

 mental properties? One is cohesion, another is gravitation, 



1 A lecture delivered at Bedford College for Women, on February 5, 

 by Sir Oliver Lodge, F. R.S. Reported from shorthand notes. 



NO. I 74 I, VOL. 67] 



and another is inertia. Concerning gravitation, we remain 

 pretty much in the dark. It is an empirical fact that a body 

 has weight, that two lumps of matter attract one another, 

 with an extremely small force when we are dealing with 

 ordinary pieces of matter, but extremely large when we 

 are dealing with astronomical masses, such as planets or 

 suns; but the cause of that gravitative attraction is not 

 known, and at present appears to have little chance of be- 

 coming known. Cohesion ten years ago was in the same 

 predicament, but cohesion now seems to be on the eve of 

 yielding up its secret. The most striking fundamental pro- 

 perty of matter, however, that we are beginning to under- 

 stand in some degree, is that of inertia. Inertia is a 

 popular term, but it is not always clearly understood what 

 is meant by it. Let me explain the meaning. It 

 may be defined as the power of overshooting the mark, 

 or the power of moving against force. It is by inertia 

 that a rifle bullet travels after it has left the gun. In 

 the barrel it is urged by force ; in the air the bullet goes 

 on against an opposing force of friction because of its 

 inertia — often in that case called the momentum. It is by 

 reason of inertia that water runs uphill ; we are sometimes 

 told that water will not flow uphill, but that is a mistake. 

 Heat will not flow uphill — heat will only flow from hot to 

 cold ; you cannot give it impetus and let it rush up of its 

 own momentum, for heat has no momentum ; it is not a 

 substance, it only goes when it is pushed, and the instant 

 you remove the force it stops. That is the case with heat, 

 but that is not the case with any form of matter — it is 

 not the case with anything possessing inertia. The water 

 from a fountain rises because of the initial velocity imparted 

 to it ; for the same reason a cricket ball rises when it is 

 thrown up ; the propelling force has ceased, but the motion 

 continues. It is the same with tides ; for three hours the 

 water is running uphill, for three hours it is running down- 

 hill. ■ The head of the inflowing water is for three hours 

 higher than the water behind it — the first three hours of the 

 flow impart to the water its momentum, and the last three 

 hours destroy that momentum gradually. The swinging 

 pendulum is another, illustration. [Having illustrated this 

 point by a liquid in a horseshoe tube, showing the return 

 to the position of equilibrium after a series of oscillations, 

 the lecturer continued.] Oscillations like that are known to 

 occur in electricity when a Leyden jar is discharged ; the 

 electricity does not go simply from the more highly charged 

 to the less highly charged and there stop, but it goes beyond, 

 it overshoots the mark and charges up that which was nega- 

 tive to positive, and then backwards and forwards, very like 

 the oscillations in the tube. Hence it would appear as if 

 electricity had a property resembling inertia. When I 

 lectured here a quarter of a century ago I should have said 

 that electricity had a property resembling inertia — I should 

 have called it a mechanical analogue — an apparent inertia, 

 simulating by inductive electromotive force the real inertia 

 of matter. I should now go further than that, and should 

 say that electricity has real inertia, just as real as matter ; 

 I should even go still further, and should say that in all 

 probability there is no inertia but electric inertia ; that the 

 inertia of matter itself is to be explained electrically. In 

 other words, what we are now arriving at gradually is an 

 electric theory of matter. We are endeavouring to explain 

 the properties of matter in terms and by means of what we 

 know concerning electricity. 



Although it may sound paradoxical to people who have 

 not studied physics, we know more about electricity than 

 we do about matter. Its properties have been more clearly 

 investigated and more clearly understood than the inertia 

 of matter, which is not understood at all. We only know 

 its behaviour : — If a body is subject to a positive force it 

 gradually increases its speed ; if it is subject to an obstruc- 

 tive force it does not move in the direction of that force 

 necessarily at once, but its motion begins to decrease, 

 gradually stopping, and ultimately reverses its direction, if 

 the force is continuous and if it is an active force. Many 

 obstructive forces are only able to oppose motion like fric- 

 tion. In the text-books a bad example of a body obeying 

 the first law of motion is given in the throwing of a stone 

 upon ice, or some smooth surface. That is a bad example, 

 because a single obstructive force acts all the time. The 

 best example to give of the first law of motion is a case 



