514 Drushel and Holden — Hydracrylic Esters. 



ing an alkaline solution of sodium hydracrylate condensation 

 products are formed and but very little sodium hydracrylate is 

 found in the residue. 



3. Hydracrylic acid in the absence of mineral acids is easily 

 esterihed directly with methyl, ethyl, propyl, isopropyi, 

 isobutyl and isoamyl alcohols by using anhydrous copper 

 sulphate as a dehydrating agent. The esters are obtained in 

 80 per cent to 90 per cent yields. 



4. The hydracrylic esters are colorless liquids with faint but 

 characteristic ethereal odor, mostly easily soluble in water ; all 

 below isoamyl are heavier than water ; all are decomposed on 

 boiling at atmospheric pressure, but are distillable without 

 decomposition under diminished pressure. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. The Volumetric Estimation of Lead. — F. D. Miles has 

 devised a new method for this determination, which depends 

 upon getting the lead into the form of sulphate, decomposing 

 this with hydrogen sulphide, filtering off the precipitate, boiling 

 off the excess of hydrogen sulphide, and finally titrating the sul- 

 phuric acid produced in the reaction. The complete conversion 

 of the usual form of lead sulphate into sulphide requires a 

 special treatment with hydrogen sulphide water in a closed flask 

 with the aid of heat and thorough agitation in the presence of 

 fragments of filter paper. The reaction is complete in the pres- 

 ence of calcium sulphate, but barium sulphate prevents a com- 

 plete conversion when an evaporation with sulphuric acid has 

 been made, so that in its presence the method requires modifica- 

 tion. The presence of considerable quantities of iron interferes 

 with the method and necessitates a double separation. The test 

 analyses given by the author show satisfactory results, and he 

 regards the method as preferable to those already in use in its 

 application to ores, but it is evident that the atomic weight of 

 lead is so high that great care is necessary in order to secure 

 accurate results. — Jour. Chem. iSoc, cvii, 988. h. l. w. 



2. /Search for an Alkali-Metal of Higher Atomic Weight than 

 Caesium. — G-. P. Baxter has found that pollucite from Paris, 

 Maine, is satisfactorily decomposed by treatment with concen- 

 trated nitric acid. Having obtained about 3| kg. of nearly pure 

 caesium nitrate from this source, he subjected this large quantity 

 of the rare material to an extensive fractional crystallization. It 

 is probable that a metal beyond caesium in the group would pos- 

 sess a less soluble nitrate, but the crystallization gave an end 



