LETTER OF TRANSMITTAL 



U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF CHEMISTRY, 

 Washington, D. C., April 4, 1910. 



SIR: I have the honor to submit for your approval a series of tech- 

 nical studies made in the Division of Drugs of this Bureau. Three 

 of these, dealing with hydrogen dioxid, glycerin, and beeswax, are 

 investigations of the quality of these commodities as found on the 

 market, the others are studies of methods of analysis presenting spe- 

 cial difficulties, or yielding results which require the greatest degree 

 of accuracy obtainable. I recommend that these papers be published 

 as Bulletin No. 150 of the Bureau of Chemistry. 

 Respectfully, 



H. W. WILEY, 



Chief of Bureau. 

 Hon. JAMES WILSON, 



Secretary of Agriculture. 

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