I08 CARNEGIE INSTITUTION OF WA.SHINGTON. 



that its degree of hydration must depend on the dihitiou of the acid — 

 a conclusion which deprives the hypothesis of all value. 

 ^ As regards the trustworthiness of the results, Mr. McBain is a very 

 careful and able workman, and it is obvious from the report itself 

 what a great deal of time and trouble he has devoted to these meas- 

 urements. He himself is quite convinced of the reliability of his 

 results, and if they were not in direct conflict with a generally 

 accepted theory I imagine no one would call them in question. 

 However, as it seems incautious to base wide-reaching generaliza- 

 tions on experiments in which so much depends on the manipula- 

 tion, I have arranged with Mr. Dawson to make a study of the de- 

 composition of acetic acid at the cathode, in the hope that it may 

 prove possible to dispense with " protecting solutions " at that elec- 

 trode, in which case the apparatus and manipulation would be much 

 simplified and Mr. McBain' s measui^ements could be checked by 

 new experiments. Mr. Dawson will also experiment with various 

 soluble anodes with the same object in view. 



H. N. Morse, Johns Hopkins University, Baltimore, Md. Grant 

 No. no. J^or development of a method for the measurement of osmotic 

 pressure. (First report is in Year Book No. 2, p. xxx.) $1,500. 



Abstract of Report. — The work of Professor Morse and Dr. J. C.W. 

 Frazer, his assistant, during the past year has been along two quite 

 distinct lines. It had been found that a porous wall, which affords 

 an effective support for the osmotic membrane, is sometimes pro- 

 duced at the potteries, though rarely, and then in only a few out of 

 many cells, and it had been discovered, through a study of thin 

 sections, that the structure of such porous walls differs in a charac- 

 teristic manner from that of others which do not adequately support 

 the membrane. The greater portion of the year has therefore been 

 devoted to the molding and burning of different clays and clay 

 mixtures and to a study of the properties of the products, the end 

 in view being a discovery of the conditions which are favorable or 

 unfavorable to the production of that peculiar structure of porous 

 wall which is known to be essential. A large number of experi- 

 ments of this kind have been made and a considerable amount of 

 data accumulated which it is thought will be of use in the solution 

 of the problem. The progress of the work has been considerably 

 retarded by the necessity of devising and constructing new ap- 

 pliances, some of which involved a large amount of preliminary 

 experimentation. 1 



