44 



K. IKEDA. 



a cork furnished with two thin tuhes, through which a current of 

 water at ahout 19°C. was maintained. The annexed figure shows the 

 phosphorus cylinder thus equipped. The surface remained perfectly 

 smooth to tlie end of the experiment, even some thin striae left by the 

 knife remaining perfectly distinct. The diminution of phosphorus 

 during the experiment was, of course, very slight, in the second case 

 not amountino- to more than one-hundredtli of a m.m. in thickness. 



The first arrangement. 



A large two mouthed bottle (1.5 litre capacity) containing air and 

 a layer of water, was surrounded 

 with water, as shown in fig. 2. 

 The side mouth was closed with a 

 caoutchouc stopper holding a 

 manometer and a short glass tube 

 with india-rubber tube and pinch- 

 cock. The phosphorus tube was 

 now introduced into the bottle 

 through the central opening 

 which it closed air-tight by 

 means of a stopper surrounding 

 its upper part. To make the air- 

 tio-htness certain, the mouths 

 were both covered with water. 

 Before beg-innino; the observation, 

 the pinch-cock was opened for a Fig. 2. 



moment to equalize the internal and external pressures. As oxida- 

 tion' .proceeded the internal pressure gradually diminished, and the 

 reading 'of the manometer repeated every five minutes gave the 

 following numbers : — 



