200 



SCIENCE. 



[N. S. Vol. XXIV. No. 607. 



The desirability of a uniform system of 

 symbols for use in works on physical, chem- 

 ical and engineering subjects has often been 

 urged ; and various systems have been sug- 

 gested, one of them by a former president 

 of this society. 



The latest proposal, made by Linders in 

 his pamphlet 'Die Formelzeichen, ' Leipsic, 

 1905, is very ambitious, and involves the 

 use of German and Russian type in addi- 

 tion to the Greek and Latin alphabets. 

 Would it be more practical to divide the 

 sciences into groups, and to fix on a uni- 

 form system of symbols for use in each 

 group, without insisting that a letter to 

 which one meaning has been assigned in 

 geometry, for instance, should not be em- 

 ployed with another meaning in chemistry ■? 

 Is it desirable to appoint a committee to 

 consider the whole question and report at 

 a subsequent meeting? 



The Influence of Calcium on Iron: 0. P. 

 Watts. (By title.) 



The Electrical Conductivity of Solutions 

 of the Alcohols in Liquid Hydroljrcnnio 

 Acids: E. H. Archibald. 

 Qualitative tests were first made to see 

 what classes of the alcohols would dissolve 

 in this solvent to give conducting solutions. 

 The liquid acid is found to be very selective 

 as regards the bodies which it will dissolve, 

 being a solvent for one alcohol but not for 

 another, although they differ but little in 

 constitution. The conductivities of solu- 

 tions of some fourteen of the alcohol bodies 

 have been measured quantitatively over a 

 considerable range of dilution. In the 

 case of the greater number of the solutions 

 the temperature coefficients have also been 

 determined. The molecular conductivity 

 in nearly all cases increases rapidly with 

 the concentration. In a few instances for 

 the more dilute solutions of the simpler 

 alcohols the molecular conductivity either 

 decreases slightly with the concentration or 



remains practically constant. As far as 

 these investigations have extended those 

 bodies which dissolve conduct the electric 

 current. The temperature coefficients are 

 in some cases positive, in some cases nega- 

 tive. 



The Electrical Conductivity of Solutions of 

 the Organic Acids in Liquid Hydro- 

 hromic and Hydrochloric Acids: E. H. 

 Archibald. 



Qualitative tests of about twenty of the 

 organic acids showed that quite a number 

 would dissolve in both solvents to give 

 conducting solutions. As far as can be 

 ascertained those acids which dissolve to 

 any extent give solutions which will con- 

 duct. The quantitative measurements 

 show that the hydrochloric acid solutions 

 have by far the greater conducting power, 

 at least in the case of nearly all the bodies 

 examined. The molecular conductivity for 

 both solvents, except in a few cases for the 

 very dilute solutions, increases with the 

 concentration. The temperature coeffi- 

 cients in all the cases examined are positive. 



The Identification of InsoluMe Phases: 



L. F. Hawley. 



By means of the solubility method the 

 formula 2PbC03 . PbCOH)^ for the basic 

 carbonate of kad was confirmed. Mixtures 

 of lead carbonate and oxide in varying 

 proportions were treated with a 20 per 

 cent, sodium acetate solution and the 

 amount of lead dissolved in 50 c.c. was de- 

 termined. The oxide was found to hydrate 

 in the presence of the carbonate until 

 sufficient hydroxide was formed to give 

 2PbC03.Pb(OH)2. The solubility re- 

 mained constant over a range of concentra- 

 tions up to two molecules of the carbonate 

 to one of the oxide, and with more than two 

 of the carbonate to one of the oxide the 

 solution was also constant, but at a lower 

 value. This shows the presence of a com- 

 pound with a formula corresponding to the 



