Sir: Washington, Aug. 5, 1863.
About a year ago Capt. Isaac R. Diller came to me with a proposition in regard to a new compound of gunpowder, the ingredients and mode of compounding, being a secret. It promised important advantages, which would be very valuable, if the promise were made good. But he did not wish to give the government the secret; nor did the government wish to buy it, without a test of it's value. For this object, the manufacture of a quantity of it became indispensable; and this again required the service of a good Chemist. Dr. Charles M. Wetherill, Chemist in your Department, was an acquaintance of Capt. Diller, and was sought by him to aid in the manufacturing of the powder. As I remember I requested you to allow him to do so, which you did. A small quantity was manufactured, and proved so far satisfactory that Capt. now, Admiral Dahlgren advised the making a larger quantity so as to test it for artillery use. I consented, and procured the Secretary of War and Secretary of the Navy, to advance, from time [to time], sums amounting in the whole to five thousand dollars, from funds under their discretionary control. Dr. Wetherill's service was again required, and again obtained, perhaps, so far as you are concerned, at my request. At the time, nothing was said, or thought of, so far as I remember, as to his receiving his salary at your Department, while engaged at the powder. Now, being brought to my mind, it seems reasonable he should receive his salary for that time, which he tells is refused. The manufacturer of the powder has required the building a good deal of expensive machinery, leaving the five thousand dollar fund no reliance for Dr. Wetherell. In fact, I suppose Capt. Diller thought the government was furnishing Dr. Wetherell, as one of it's officers, to make the experiment.
Dr. Wetherell presents another question, which is as to the amount of his permanent or general Salary. I see that the law fixes the salaries of a class to which the chemist belongs ``corresponding to the salaries of similar officers in other Departments'' and I do not see that the law assigns me any duty or discretion about it. All I can do is to give a sort of legal opinion, that his salary should be fixed according to the law. I do wish these questions