Chemistry and Physics. 249 



slight to affect the result. But even this influence may be entirely 

 eliminated by previous distillation with an alkali solution. 



In subsequent papers Tratjbe has extended this •method to the 

 estimation of the strength of ethyl alcohol and of acetic acid, and 

 to the determination of the alcoholic strength of wine, beer and 

 liqueurs. He gives carefully prepared tables of the number of 

 drops given by mixtures of absolute alcohol and water varying by 

 tenths from to 10 per cent by weight, and in temperature by de- 

 grees from 10° to 30° ; those given by pure water at 15° being 100. 

 At a concentration of 20 per cent, an error of - 2 drop in 100, cor- 

 responds to an error of only # 1 per cent in the amount of alcohol. 

 The acetic acid table is similar, but its range in temperature is 

 only from 11° to 29° in 2° stages. The results of the method as 

 applied to wine and beer are given and show that it maybe relied 

 on within 0'1 per cent, when used on the distillate. — Ber. Berl. 

 Ghent. Ges., xx, 2644, 2824, 2S29, 2831, Oct., Nov., 1887. 



G. F. B. 



2. On Apantlesis ; a Separation of the Constituents of a 

 Solution by Rise of Temperature, — Having observed that on sev- 

 eral occasions the upper part of an alcohol thermometer column, 

 after having slowly risen from a considerable contraction, was 

 colorless, and that no deposit of the coloring matter (probably 

 cochineal) had taken place, Mallet was led to make further 

 experiments in this direction. It seemed as if the colorless 

 alcohol had by its expansion separated itself from a still perfect 

 solution left behind. The solutions used were partly aqueous 

 partly alcoholic, of several colloid substances, starch, tannin, 

 cai'amel, albumen and gelatin. Each solution was placed in a 

 flask of about half a liter capacity, surrounded with ice, the 

 mouth of the flask being closed with a cork carrying a glass 

 tube about 4 mm in diameter and 15 or 20 cm long, having a glass 

 tap near its middle point The ice being removed the liquid 

 was allowed to rise in temperature until the column, originally a 

 centimeter or two below the tap, was as much above it. The tap 

 was now closed and the liquid above it submitted to examination 

 in comparison with an equal volume of the original solution. In 

 all cases the liquid above the tap contained a less amount of 

 material in solution, in some cases very notably less ; while in 

 two or three cases there was practically none. As all the solu- 

 tions were carefully filtered at the outset, there could have been 

 no settling of particles. The conditions influencing the result 

 seem to be: first the proportion of the colloid solid in solution ; 

 and second, the time occupied in the rise of temperature. The 

 author has given the name apantlesis to this phenomenon, signify- 

 ing a draining away of some of the molecules of the solvent from 

 those of the colloid while the solution was undergoing expansion. 

 — Chem. JVews, lvi, 146, Oct., 1 887. G. F. b. 



3. On the Properties of Fluorine. — Moissan has published in 

 full his investigation upon the isolation of fluorine, made in 

 Debray's laboratory. As we have already noticed his methods* 



*See this Journal for March, 1887, p. 236. 



