Surgeon General’s Office
Washington City, D.C.
July 23d 1866
Prof. H.L. Smith
Dear Sir,
Yours of the 19th came duly to hand and I thank you very much for the growing slides. They are very ingenious and I shall value them the more as being your work. You know that the whole energy of the microscopic labor under my direction is directed towards Pathology and I only turned to the Diatomacea as test objects in developing the photographic process which we are using with the most complete success on the tissues. Still as I feel we have mastered the whole matter of microphotography, I should be glad to photograph a few more diatoms by way of showing those who are not interested in Pathology how good and reliable our process is and of inducing them to use it also. Should you therefore care to take the trouble of sending us a few specimens of carefully selected single diatoms for the Museum, we would in the course of the summer and fall undertake their photography, and cheerfully furnish you copies of our results. I think Wales really a clever young man. He has made me a number of pieces of apparatus, which with rare exceptions have given perfect satisfaction. His photographic 4/10, 1/8 and amplified leave little to be desired further. I have just received from him a 1/5 for photography, which however I have not tried. All of these lenses are made on Rutherford’s formula and can only be satisfactorily used for vision when illuminated with violet light. He is now making me a 1/16 on the same principle, from which I expect great things. He has improved enormously since I first knew him. In fact in /62 I saw lenses of his in the hands of various parties and regarded them as very inferior. It was not until 1864 that he began to make work of the highest class and I do not think that at present he would claim even to have made a 1/16 of the best quality. Barnard objects to his 4/10 that it is really a ¼ and so perhaps it is, but it is the habit of nearly all opticians to misstate the power of their lenses and I find his run quite parallel in nomenclature to those of Smith + Beck and other English opticians.
I am, Sincerely,
signedd. J.J. Woodward
Bvt. Maj. and Ass’t. Surg. U.S.A.
