HOW SAVAGES OBTAIN FIRE.

Dominion, Volume 6, Issue 1721, 11 April 1913, Page 6

HOW SAVAGES OBTAIN FIRE.

... ■ : —♦ ..: SIR J) J. THOMSON THROWS LIGHT .ON AN "OLD Mi'STERY. In mi address at tlie Royal Institution, ; London, recently, oil the properties of'tha atom, Professor Sir J. J.' Thomson resumed his discussion on the number of atoms or molecules there are in, a given weight or a given .volume of a substance, intl in de.iiilig with experiments in connection with com pressed air he threw nn interesting sidelight 011 Die means or ol> taming lire utilised by, two particular native races. "It is one of the most extraordinary tilings in connection with the habits of savage races," he said, "that there nro actually two tribes-which use this method -the heat generated by the compression of air—in order to get fire. It is an extremely difficult problem to know how they could liavo ever E»it this idea. , I am iiuito sure'it was not obtained by attend- . ing leclu'rns 011 these things—(laughter)— but in some way was gained perhaps fep . practical experience." One could understand that by observing branches rubbing against each other men might have got the idea of getting fire by rubbing one piece of wood against another, ' but tho problem of getting fire by compressed air was by no means easy to-do in an ordinary laboratory. Probably, one ■ would make several unsuccessful attempts before 0110 succeeded, in fretting tho piece ijf tinder alight. "The only thing I can think of," h# added, "is that perhaps these are-tribes that use blow-pipes, the blow-pips may liavo got choked up or something of tho kind, and after vigorous efforts to drive out the obstruction they may have managed to set .the thing, or some part of it, alight, and in that way come across.this, t method of getting ' "It is.one of the most interesting things in connection with the habits of those tribes that two different tribes, apparently . in no way connected with each other, Bhonld liavo arrived at. this very complicated method of producing fire.' , Professor Thomson said scientists believed they knew with considerable accuracy tho number of systems—molecules and atoms—contained in any volume of " ' gas, but each of those systems had a popu- , lation of its own. The problem of count- ■ ing the imputation tf the inoleculo—tho number of ••orpuscles in a molecule—was more dillbult than counting the number of molecules. One of tho methods depended upon tho proDcrtios of tho lioutgen Hays. It was found that tho number of, corpuscles was proportionate to th(Milomic' weight. .