32 J. SAKÜKAI: MODIFICATION OF BECKMANX'S BOILING 



I veiitnre to say, is a great advnntnge. The oij]y costly part of the 

 apparatus is tlic thermometer, hut for good and accurate woi-k in 

 most of tlie physico-chemical in(]uiries, ii delicate tliermometer is 

 indispensahle and, after all, its cost is not disproportionate to the 

 important services it can rerider. 



]}[o'Jc of Worhiurj. For working with tlie apparatus descrihcd 

 above, I beoin bv inserting the tube e into one limb of the br,iling 

 vessel, lixiiif it ])y meisns of the cork c. Small glass beads are then 

 introduced into the boiling vessel through the other limb, till they 

 quite fill tlie bent ])ortion of the latter. (IV^-kmann recommends tlie 

 nse of small garnets or glass beads for preventing local differences of 

 temperature, and I find them also very effective for thoroughly 

 mixing the vapour passed in with the boiling liquid and thus 

 establishing a perfect uniformity of temperature.) The experimental 

 liquid is now poured in, so that it occupies a space of 3 or 4 centimeters 

 above the level of the glass beads in the oj'cn limb, and the latter is 

 then closed by the cork carrying ilie thermometer. The lid of the 

 asbestos box is next slipped down the two lim1)s <^f the U-tube, which 

 pass through two holes previously bored in it in proper positions, and 

 the boiling vessel, after having been properly enclosed in the asbestos 

 box and supported on the ring of a retort-stand, is connected, on the 

 one side, with the boiler and, on the other, Avith the side tube and 

 condenser, as shown in the figure. 



First the boiler, half filled with the solvent, and then the boiling- 

 vessel are heated by carefully reguLited lamps, the stop-cocks r and s 

 both open ; and, when the li(juid in both vessels begins to boil [pro- 

 perly, the stop-cock v is closed, and the two lam])s Aery carefully 

 regulated, so that the height of the column of the boiling lixpu'd 

 remains, as nearly as can be judged, level with the lid of the asbesto.s 

 box for, at least, a quarter of an hour. This circumstance is used as 



