TRANSACTIONS OF SECTION B. GOl 



done by including one leg of a bent sypbon witbin tbe vessel while the other opens 

 outside. Tbe object of the syplion is that tbe air, enclosed by the vessel and com- 

 pressed by its immersion into the water, may escape through tbe hollow sypbon. 

 When the air ceases to issue, tbe sypbon is immediately withdrawn, so tliat no air 

 can afterwards get into the glass. In a short time you will see the water gradually 

 rising into tbe vessel while the candle still burns.' 



In other experiments be burnt camphor and sulphur supported on a shelf in the 

 inverted vessel. The water rose, he says, because, owing to the disappearance of 

 the fire-air, tbe air left could not resist the pressure of tbe atmosphere outside. 

 When the combustibles were extinguished it was impossible to kindle them again 

 by means of tbe sun's rays concentrated on them by a burning glass. The residual 

 air was no more able to support combustion than the vacuum of Boyle's engine. 

 Again, tbe respiration of animals in the closed space was shown to diminish the 

 air, and to render it incapable of supporting combustion ; the fire-air was as 

 necessary for life as for flame. The larger portion of the air was something 

 entirely different from fire-air, and incapable of supporting life or combustion. I 

 beheve this to be the first definite statement founded on experiment that the air is 

 composed of two distinct gases. 



I have given tbe fundamental facts in chemistry we owe to Mayow ; the limits 

 of his work are sufficiently obvious. He detected tbe existence of what we call 

 oxygen gas in the air, and demonstrated some of its most remarkable properties. 

 He did not isolate the gas, or show what became of it in combustion ; be did not 

 always distinguish between the gas itself and tbe heat produced by its action. But 

 the advance he made was extraordinary — not so much in the conclusions lie drew 

 as in the experiments and arguments be founded them on. Compare him for a 

 moment with another writer who had previously expressed similar views concerning 

 tbe calcination of metals. Jean Rey, of Perigourd, a witty and shrewd physician, 

 published in 1630 a series of essays attributing tbe increase in weight of metals on 

 calcination to the fixation of the air. ' When asked,' he writes, ' why tin and lead 

 increase in weight on calcination, I reply and gloriously maintain that this increase 

 comes from tbe air which is thickened and made heavy and adhesive by tbe long 

 continued heat of the furnace. This air mingles with the calx and attaches itself 

 to the smallest particles.' The reply is good, but the reasons that gloriously main- 

 tain it are not altogether conclusive. I can only give two of them : (1) The air 

 has weight. — This is shown by the increase in velocity of heavy bodies falling to 

 the earth, because as the body approaches the earth it subtends a wider angle from 

 the centre of the earth, and receives more shocks from the particles of air. Again, 

 although tbe air appears to weigh nothing on the balance, this is because we weigh 

 it in air; it loses its weight, just as water weighs nothing in water. Fire has 

 weight too, and should we ever find ourselves in a region where fire is the pre- 

 dominant element, we shall be able to prove the statement in the same way. 

 (2) Fire can thicken and make air heavy. — Stand a cannon upright and put a red- 

 hot ball into it. You must admit that the air in the gun is so small in quantity 

 that it will be heated to the same temperature as the ball. Nevertheless you can 

 hold your hand in the mouth of the gun at first, but in a short time you cannot 

 do 80. Not that the air has got hotter, it is cooling all tbe time ; it is because the 

 air is thickened. Now if you drop a fleece of wool into the mouth, it will not 

 descend, and if you push it in, it will come up again, proving the air is heavier. 

 Lastly the air is seen to tremble over the mouth of tbe gun, and objects seen 

 through it are blurred. This is due to the thickening, it cannot be due to a motion 

 of the air ; ' for I see,' he says, ' a lady's beauty quite distinctly through tbe air she 

 flutters with her fan.' 



From what has been stated it will be clear that the Oxford School of Chemistry 

 was a school of research. Boyle gave no instruction in tbe ordinary sense ; and, 

 indeed, bad no official connection with the University. But that be thought instruc- 

 tion in chemistry should be given in the University is obvious from the fact that 

 he brought over a chemist from Strasburg, and set him up as a lecturer with rooms 

 next his own and the use of his laboratory. Of these lectures we find a quaint 

 account in Anthony Wood's diary : — 



