76 THE BUREAU OF SCIENCE 



It has been the constant endeavor of cement manufacturers 

 and users to develop a quick and reliable test for Portland 

 cement, and recent experiments with the autoclave test indicate 

 a possible solution of the problem. However, the autoclave test 

 cannot become of value until the significance of the results 

 obtained are thoroughly understood. A thorough study of this 

 test has been begun, but the investigation has only reached the 

 preliminary stage. 



Samples of soft rock from Nueva Ecija submitted by the 

 Bureau of Public Works for valuation as a road material proved 

 to be hardened clay which apparently possessed many of the 

 properties of a material suitable for the manufacture of vitrified 

 brick. A few trial mixtures gave very promising results as 

 well as evidence that the clay would have to undergo special 

 treatment for use in paving brick. Owing largely to the energy 

 pf Mr. King, who worked on the problem outside of the regular 

 working hours throughout the hot season, we have obtained 

 very satisfactory products. 



Our investigation of raw materials to determine their suit- 

 ability for the manufacture of lime; hydraulic, Roman, and 

 Portland cement; and sand-lime brick has been continued, and 

 materials which proved satisfactory will be subjected to the con- 

 ditions of actual manufacture in a new lime kiln of 500 pounds' 

 capacity, which we have just completed. 



A large number of problems of industrial and economic im- 

 portance await time and opportunity to investigate them. 



DIVISION OF ORGANIC CHEMISTRY 



Personnel. — Dr. Harry D. Gibbs, chief of the division of 

 organic chemistry and assistant to the director, has been absent 

 on leave since the beginning of the calendar year, and the work 

 of the division has been under the direct supervision of Mr. R. 

 R. Williams and Dr. D. S. Pratt. Mr. Williams resigned on 

 June 15, to go into commercial work in Manila, and Mr. J. del 

 Rosario and Mr. E. R. Dovey resigned on September 30, 1912, 

 and June 1, 1913, respectively. Mr. Williams will continue to 

 devote a portion of his time to research work in the Bureau. 



ROUTINE WORK 



The routine work alone of the division has been of as wide a 

 variety as in previous years, and has practically consumed the 

 time of three chemists and a part of that of others. Aside from 

 two classes of samples mentioned below, this work has shown 



