LETTER OF SUBMITTAL. 



U. S. Depart]vient of Agriculture, 



Bureau of Chemistry, 

 WasMngton, D. C, March 20, 1912. 

 Sir: I have the honor to submit for your inspection and approval 

 a manuscript giving the results of an investigation of methods for 

 the determination of hthium, prepared by W. W." Skinner, Chief, 

 and W. D. Collins, First Assistant Chemist, of the Water Laboratory 

 of the Miscellaneous Division. 



In the enforcement of the food and drugs act it was found necessary 

 to study carefully methods for the determination of small amounts 

 of lithium, such as exist in most mineral waters, some soft drinks, etc. 

 As a result of this study the authors have perfected a quantitative 

 spectroscopic method for this purpose which is of great value in the 

 work we are doing. This method has been given a thorough test 

 extending over a period of two years and has been adopted as a part 

 of our regular technique in mineral-water analyses. The manu- 

 script transmitted herewith gives the method developed by Messrs. 

 Skinner and Collins, together with a comprehensive review of the 

 literature of the subject of the determmation of lithium, and makes 

 a valuable addition to the technical papers prepared in this bureau. 

 I recommend that the report be published as a bulletin of this bureau. 

 Respectfully, 



J. K. Haywood, 

 Chief Miscellaneous Division. 

 R. E. Doolittle, 



Acting Chief Bureau of Chemistry. 

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