k/ 



THE PHILIPPINE 



JOURNAL OF SCIENCE 



ALVIN J. COX, M. A., Ph. D. 



GENERAL EDITOR 



Section A 



CHEMICAL AND GEOLOGICAL SCIENCES 

 AND THE INDUSTRIES 



EDITED WITH THE COOPERATION OF 



H. C. BRILL, Ph. D. ; J. R. WRIGHT, Ph. D. ; G. W. HEISE, M. S. 



T. DAR JUAN, A.B., Phar. D.; A. H. WELLS, A. B. 



R. C. MCGREGOR, A. B. ; H. E, KUPFER, A. B. 



Volume XIII 



1918 



With 26 Plates and 62 Text Figures 



O GO. 7/7- 



MANILA 



BUREAU OF PRINTING 



1918 



