CHEMISTRY. 351 



contrary indications of others are probably to be ascribed to the fact 

 that they ignored the inclusions in the precipitate, which may seri- 

 ously complicate the issue. The outcome of the recent investigation 

 shows that the best form of coulometer is that in which the anode is 

 inclosed in a porous cup, the level of the anolyte being kept always 

 below that of the surrounding solution. The silver precipitate should 

 be ignited at a redness just barely visible in a dark room, and a small 

 correction should be applied for the trace of silver remaining from the 

 included mother liquor. 



3. The Electrochemical Investigation of Concentrated Thallium Amalgams. 



This investigation, begun three years ago, was carried to a much 

 further state of advancement during the past academic year with the 

 help of Dr. Farrington Daniels. Not only were potentials between the 

 various concentrations of liquid thallium amalgams measured with the 

 greatest attainable accuracy, but also heats of dilutions, densities, 

 and heat capacities were studied by new and successful methods. 

 The outcome furnishes a great quantity of exact thermodynamic data 

 concerning the electrochemical behavior of these amalgams, and 

 provides the basis for interesting theoretical discussion. It is hoped 

 that before long this work may be made public. 



4. The Heat of Solution of Metals. 



With the help of Dr. T. Thorvaldson, the heat of solution of metals 

 was studied in great detail by means of a new and improved method. 

 In the course of this work, because of the unsatisfactoriness of the best 

 standard thermometers, a new thermodynamic method of verifying 

 the temperature scale was worked out in detail, and this furnished a 

 more satisfactory basis for the computation of the present results, as 

 well as other thermochemical results recently secured in this laboratory. 



5. Heats of Combustion of Organic Substances. 

 Another elaborate thermochemical investigation was continued with 

 the help of Dr. H. S. Davis. This concerned the heats of combustion of 

 organic substances. Defects in the older methods were discovered and 

 a series of results obtained which it is believed are the most accurate of 

 any thus far executed. Eighteen organic substances w^re burned 

 quantitatively in an improved adiabatic calorimeter during the course 

 of this work. 



6. Heats of Neutralization and Dilution of Strong Acids and Bases. 



Dr. A. W. Rowe continued the investigation concerning the heat of 

 neutralization and dilution of strong acids and bases. Lithium and 

 caesium salts were added to the list, and various data necessary for the 

 rounding out of the thermodynamic treatment were secured. Although 

 this research has already yielded one long paper, much more remains 

 to be' published concerning it. It places our knowledge of the heat 

 of neutralization of the acids and alkalis upon an entirely new basis. 



