242 



SCIENCE 



[N. S. Vol. XXVI. No. 660 



Silver can be separated eleetrolytically 

 from copper in a tartrate solution by a con- 

 stant voltage method. Vigorous stirring is 

 essential if a good deposit of silver is to be 

 obtained. 



Some Unique Conductivity Curves: Ed- 

 WAED C. Franklin and Haeet D. Gibes, 

 Leland Stanford University. 

 With solutions of silver nitrate in methyl- 

 amine the molecular conductivity first in- 

 creases with increasing dilution, then passes 

 through a maximum followed by a mini- 

 mum. This abnormal behavior is probably 

 the resultant of three factors, the self-ion- 

 ization of the salt, the dissociating power 

 of the solvent and the viscosity of the sol- 

 vent. 



A Dynamic Method for Determining the 

 Temperature Pressure Curves of some 

 Monovariant Systems of the Second and 

 Higher Orders and its Application to a 

 Dissociation: W. D. Horn, Bryn Mawr. 

 This paper will appear in full in the 



American Chemical Journal. 



Recent Advances in Electrolytic Analysis: 

 Edgae F. Smith. Reported by title. 



Electrical Conductivity of Solutions in 

 Ethylamine: F. L. Shinn. Reported by 

 title. 



industrial chemistry 



W. H. Ellis, chairman 



Some Reactions during Water Treatment: 



Edward Bartow and J. M. Lindgren, 



The University of Illinois. 



A series of tests was made to determine 

 the amount of calcium and magnesium re- 

 moved by each addition of reagent. The 

 mineral matter in the water consisted 

 almost entirely of the bi-carbonates of 

 sodium, magnesium and calcium. 



It was found that after the neutralization 

 of carbon dioxide the calcium is removed. 

 A reaction then takes place between the 



reagent and sodium bicarbonate, when pres- 

 ent, and finally, magnesium is removed. 

 The reactions within the limits of solubility 

 of the precipitates take place in order 

 almost quantitatively, with but little over- 

 lapping. 



The experiments suggest the necessity 

 for considering the presence of sodium 

 bicarbonate in water treatment. 



Some Experiments to Determine the 



Amount of Volatile Matter in Coal: A. 



Bement, American Trust Building, 



Chicago. 



To ensure that no combustion would oc- 

 cur, an inert gas was continually passed 

 through the crucible under slight pressure 

 during the heating process. For conve- 

 nience in preparation hydrogen was em- 

 ployed and the charge was heated by an 

 ordinary Bunsen burner. The result was, 

 that even after heating for periods of 100 

 and 120 hours, a loss still continued, and 

 the indications were that it would have 

 gone on for additional periods of equal 

 lengths of time, at least. 



Deflocculated Graphite: Edward G. Ache- 

 son, The Acheson Company, Niagara 

 Falls. 



Experiments on clays, carried out in the 

 year 1901, showed that by adding vegetable 

 extracts— gallotannic acid, extract of straw 

 —to moderately plastic weak clays, their 

 plasticity was increased, the amount of 

 water required to produce a given degree 

 of fluidity was lessened, and the size of the 

 particles in suspension was much reduced. 

 The effect on finely divided graphite is 

 much the same ; and by the use of a little 

 gallotannic acid and a few drops of am- 

 monia, suspensions may be prepared which 

 last indefinitely. Extensive tests are now 

 being made to determine the value of this 

 " deflocculated graphite " as a lubricant, 

 with most encouraging results. 



