950 



SCIENCE 



[N. S. Vol. XLII. No. 1096 



lution, that is, that it does not materially influence 

 the deviation from the law of mass action, is af- 

 forded by a comparison of the magnitude of the 

 deviation at various ion concentrations for dif- 

 ferent electrolytes. Thus at the ion concentration 

 0.001 N, d for KCl equals 0.29, for dichloracetio d 

 is less than 0.003 and for acetic acid it has a 

 small negative value. At the ion concentration 

 0.05 N, the values for the first two electrolytes are 

 0.40 and 0.06, respectively. Evidently there is no 

 parallelism between ion concentration and the 

 magnitude of the deviation from the law of mass 

 action. The former does not control the latter. 

 The osmotic pressure or activity of the undis- 

 sociated molecules depends largely upon their 

 type. They are more abnormal the stronger the 

 electrolyte. 

 The Calorimetrio Determination of Ferrous and 



Ferric Iron: 0. L. Barnebet. 

 Differential lodimetry. I. The Titration of Perio- 

 dates, lodates, Bromates and Chlorates in the 

 Presence of Each Other and in the Presence of 

 Perchlorates : 0. L. Barnebey. 

 Molecular Weights of Gases ly an Evaporation 

 Method: H. L. Trumbull. 



That liquids evaporate into different gases at 

 different rates was first pointed out by Stefan. 

 Winckelmann, and Guglielmo extended the work 

 of Stefan, to include many liquids, and a general 

 agreement between all their results was noted, 

 viz.: that evaporation is most rapid into hydrogen 

 and correspondingly less rapid into heavier gases. 

 The methods employed by the earlier investigators 

 were not all that could be desired, being at fault ia 

 the matters of temperature control, elimination of 

 wind currents, and the employment of a height 

 loss, rather than a weight loss method. 



The object of this investigation was to find a 

 simple and accurate method for the measurement 

 of rates of evaporation of water into different 

 gases, with a view to the relations between the 

 rates and densities of the gases used. These ex- 

 periments were conducted in a perfectly dry at- 

 mosphere, free from air currents, at a constant 

 temperature of 25°.07 ± 0°.01, and by a weight 

 loss method. A comparison of the evaporation 

 constants obtained in this experiment leads to the 

 following results. The predicted values of the 

 relative diffusion rates on the basis of Graham's 

 law are hydrogen to air, 3.79, hydrogen to CO,, 

 4.67, air to 00,, 1.24. The means of the corre- 

 sponding rates by this evaporation method are 

 3.37, 4.68, and 1.393. Various applications are 

 cited. 



Production of Potassium Chlorate from Kelp: H. 



L. Trumbull and H. C. Howard. 



Electrolysis of a solution obtained by pressing 

 and lixiviating the kelp produces chlorates with a 

 current efficiency of 50 per cent, and an energy 

 expenditure of 7K.W.H. per pound of chlorate. 

 No purification of the raw material is required. 

 Because of the great difference in solubility of the 

 sodium and the potassium chlorates the latter is 

 easily obtained in a pure state. 



DIVISION OP industrial CHEMISTS AND CHEMICAL 

 ENGINEERS 



Geo. p. Adamson, Chairman 

 S. H. Salisbury, Jr., Secretary 

 Additional papers not read in symposiums. 

 Refining Vegetable Oils: Chas. Baskerville. 

 The Belation of Water Poicer to Chemical Indus- 

 try: Henry J. Pierce. 

 "Viscosimeters'' : R. P. MacMichael. 

 The Function of Coohing Fossil Resins in Varnish 

 Manufacture: W. L. Jeffries and Chas. H. 

 Hertt. 

 A Test of a Surface Comiustion Furnace: E. 

 Schramm and J. E. Cain. 



In view of the fact that the surface combustion 

 process appeared to offer many advantages for 

 high-temperature laboratory furnaces, it was de- 

 cided to submit a crucible furnace of this type to 

 a thorough test. For the purpose, the furnace waa 

 equipped with meters on the gas and air lines and 

 with a chimney to permit the collection of flue gas 

 samples. In several runs the mixture proportions 

 were maintained constant, while varying the rate 

 of gas consumption. Temperatures were read by 

 a Hollborn-Kurlbaum optical pyrometer. The 

 highest temperature reached was 1675° C, at 

 which point the alundum mufSe failed. The test 

 established that complete combustion could be at- 

 tained without excess air, that the best air: gas 

 ratio was 5.5, and that a 20-per-cent. excess of air 

 caused a lowering of furnace temperature of 100°. 



biological chemistry division 



Carl L. Alsberg, Chairman 



I. K. Phelps, Secretary 



Mutual Action of Similarly Charged Colloids: W. 



D. Bancroft. 

 Adsorption of Colloids by Liquids: W. D. Ban- 

 croft. 

 Formation- of Surface Films: W. D'. Bancroft. 

 A Search for Sydrocyanic Acid in the Caprifoli- 

 acew: C. L. Alsberg. 



