Chemistry and Physics. 258 
apparatus is heronens: a ges and by means ofa spring clip, 
the liquid to be examined, whi h is contained in the bulb, is 
the cotton wool. The spring clip is then closed and the tube 
become constant. A little air is then admitted and a second read- 
a solid is to be submitted to experiments, the bulb of the ther- 
mometer is previously covered with it by dipping it repeatedly in 
the melted substa nce. The results of a determination of vapor- 
pressure are given in the case of acetic acid, the curve yielded b 
them when plotted ap nee coincident with that obtained 
by the usual process when air moisture are rigorously ex- 
cluded, the ene being ee HA y pure. at Chem. oe wine 
42, J ae 5. 
Non- nsformation oy 4 Bose ae wae pais 
by direct synthesis —Since the of form of periodic oxide 
is positive, and is equal to 44, or pers ty Smoniie to Thomsen, 
We should expect that iodine ae oxygen would unite directly to 
form this subs Weusare bas made a series of experiments 
to test this question seaeiiied atin In the first, oxygen charged 
With iodine vapor was passed through a glass tube containing a 
plug of platinized asbestus 7 or 8 cm. long, and heated to a tem- 
perature of 200° in an air bath. After two hows, the tube was 
Washed out with water and the solution examined; but no trace 
of the pentoxide was detected. In the others, the temperature 
Was raised to 250°, 290° and finally ee a dark red heat; but with 
similar result, By means of a Hofmann vapor de ensity apparatus 
the mixture of oxygen and iodine was haa ed by aniline vapor to 
192°, in presence of four beads of platinum sponge. Finally the 
ponding ee ah and to platinom | oe abrom methods 
of analysis were emplo ah In the first the saa os deter- 
mined by igniting the compound in a gent of hydrogen and in 
the second by decbchyid precipitation. When potassium salts 
Were used the results were checked by evaporating and weighing 
the Solution of the residue. For the investigation 300 grams of 
pee inum were used, purified by the Bunsen-Schneider method. 
he Pepin raga was — by a platinum sponge with 
ve, So.—TarEp rep Serres, Vou. XXIX. No. 171.—Mancu, 1 
