COMMITTEES ON BEHALF OF THE GOVERNMENT 255 



of Engraving and Printing which completed them and delivered 

 them to the office of the Commissioner of Internal Revenue to 

 be issued. 



In order to ascertain whether these changes were likely to be 

 effective, the Acting Commissioner of Internal Revenue on April 

 13, 1870, sent some specimens of the stamps to the Academy 

 with the request that they be examined by it, with regard to 

 their sensitiveness to the action of chemicals. This request was 

 contained in the following letter "^ addressed to Joseph Henry, 

 President of the Academy: 



" Treasury Department, Office of Internal Revenue, 



" Washington, April 13, 1870. 



" Sir : In accordance with the third Section of the Act of Congress incor- 

 porating the National Academy of Sciences, I have the honor to submit herewith 

 specimens of proposed Internal Revenue Stamps for examination and report with 

 reference to their sensitiveness to chemical agencies applied for the purpose of 

 removing ink, cancellation marks, and their durability under ordinary usage. 



" Very respectfully, 



" J. W. Douglass, 



"Acting Commissioner. 

 " Prof. Joseph Henry, 



"President National Academy of Sciences, Washington, D. C." 



A committee consisting of Wolcott Gibbs, Samuel W. John- 

 son and John Torrey was at once appointed to consider the 

 subject. The records of the Academy do not contain the report 

 of the committee but we may infer that it was to the effect that 

 the changes introduced would prevent fraud, as the Commis- 

 sioner remarked in the following year: 



" It is believed that the stamps now being furnished under the contracts alluded 

 to, cannot be tampered with. Especially is this thought to be the case with the 

 adhesive, and tobacco, snuff, and cigar stamps printed on chameleon paper. This 

 paper so effectually changes its color upon the application of chemical agents 

 employed for the restoring of stamps for re-use, as to render restoration to its 

 original state impossible." °° 



™Proc. Nat. Acad. Sci., vol. i, p. 76. 



°' Rep. Comm. Int. Rev. for 1870-71, p. xlv. 



