LAVOISIER 3 



in this his first important research he employs the balance 

 " the essential instrument of all chemical research." 

 He heated water in a closed and weighed glass vessel for 

 a hundred and one days, and at the termination of the 

 experiment found that the vessel had lost 17*4 grains, 

 and on evaporation of the water a solid residue weighing 

 20*4 grains was obtained the excess being due to unavoid- 

 able experimental error. Lavoisier concluded that water 

 when heated was not transmuted into earth, which was 

 the theory entertained by the alchemists and some of the 

 pneumatic chemists. He proved that the water dis- 

 solved some of the constituents of the glass a conclusion 

 confirmed by Scheele. This research had a far-reaching 

 and an important bearing on the notions or theories of 

 the times theories that had existed for centuries were 

 to be swept away by his clinching experimental proof of 

 their absurdity ; the art of alchemy and the pursuit of 

 the philosopher's stone was rendered futile; but, above 

 all, the experiments proved that the old alchemical idea 

 of the transmutation to be false ; l and it led him to 



1 That a distinguished chemist should in the twentieth century 

 lecture on " The Transmutation of the Elements," would have seemed 

 absurd and impossible to any of our scientific forefathers. Yet this 

 was the title of a lecture delivered at the London Institution on 28th 

 January 1907 by Sir William Ramsay, who showed the influence of 

 electricity on the break up of matter. Radium has shaken our ideas 

 about the ultimate atom and the elements, and is always, though 

 slowly, breaking up and giving off various products helium among 

 others. The ultra-violet radiations tend to break up metals. These 

 things, viewed in connection with the latest electrical theories, appear 



