The Einhorn (Unicorn) Press

The electric microscope probably first appeared at some point in antiquity, after the Egyptian priests and others had discovered the carbon arc light.  However, this technology was apparently lost at some time during the Dark Ages, and did not reappear until the nineteenth century.  The is evidenced in a report in the October 1870 issue of Harper’s New Monthly Magazine, which expounded on the electric arc light’s camera-friendly merits in conjunction with the use of the microscope in the United States.  In an article therein, entitled “Electric Light in Photography,” the writer informs us that

“Among the most interesting communications made before the American National Academy of Sciences, at its last meeting, at Washington, in April, was one by Dr. Woodward, of the Army Medical Museum, in regard to the use of the electric light in photography.  Occupied for many years in the preparation of photographic negatives of microscopic objects, the author experienced great inconvenience from the difficulty of working at times when the sun did not shine sufficiently for his purposes; and, after trying various kinds of artificial illumination, he finally came to the conclusion that the electric light, under some circumstances, was to be preferred even to the sun itself, since photographs could be taken at any time of day or night, and after a much shorter exposure than to the sunlight.  The magnesium light was found to have some advantages, especially when the object was not to be magnified more than one thousand times; but for average work, especially under very high powers, the electric light was found to surpass all its rivals.

 

 

 

 

“The apparatus used was a Duboscq’s lamp kept going by a battery of fifty small Grove’s elements.  Seven and a half pounds of strong commercial nitric acid, with three of sulfuric diluted with ten times the quantity of water, were sufficient to charge the battery and keep a continuous light for three or four hours, during which time from twelve to thirty or more photographs could be produced, the number varying with the character of the subject and the amount of preparation required.  Dr. Woodward states that for a negative of one thousand diameters, about thirty seconds are sufficient for some objects, while for others about three minutes were required.  This light was found to be perfectly adapted for producing photographs of the soft tissues with any power under a thousand diameters.”