The Minute Anatomy of Two Cases of Cancer. 
Ill 
stiffer than ordinary plate paper, and therefore quite suitable for 
book purposes. 
In the United States this process is employed by the American 
Photo-relief Printing Company, No. 1002, Arch Street, Phila- 
delphia, under the supervision of Mr. John Carbutt, who has 
reproduced three of my negatives of microscopic objects, viz. a 
photograph of a section of ovary magnified 400 diameters, of which 
five hundred copies were printed, mounted on stiff cardboard, and 
used among the illustrations of my report on photographing histo- 
logical preparations by sunlight; a photograph of Amjfhifleura 
pellucida, in illustration of a paper published in the £ American 
Naturalist ’ for April, 1872, and a photograph of two frustules of 
Triceratium firnbriatum, in illustration of a paper published in 
the Chicago ‘Lens’ for April, 1872. Large editions of the last 
two prints were struck off for the journals named. They were 
mounted on plate paper. 
In quality these prints were almost fully equal to fine silver 
prints, which they closely resembled, but the editions were much 
more uniform than would have been possible had silver prints been 
used. The cost, moreover, was considerably less than that of 
silver prints, and the negatives were returned to me wholly 
uninjured, while they would have been much damaged if not quite 
destroyed had an equal number of silver prints been made from 
them. 
The Albertype process is employed in New York by the Photo- 
Plate Printing Company, under the supervision of Mr. E. Bierstadt, 
No. 932, Broadway. In this process a printing surface (not a 
relief) is produced on a gelatine film by the action of light, through 
the negative, on certain chemicals contained in the film. The 
surface thus produced, when properly inked, yields in the press an 
impression on paper, in which the details of the original negative 
are very well preserved. The prints may be made on either plain 
or enamelled paper ; in the latter case they closely resemble silver 
prints on albumen paper, in the former they are like silver prints 
on plain paper. In either case they give a clean white margin, 
and therefore do not require to be mounted as Woodbury prints do, 
but are at once ready for binding. Moreover, proper descriptive 
lettering is readily added to the plate. If suitable ink is employed 
the prints are as permanent as lithographs or other engravings. 
Two of my negatives were placed in Mr. Bierstadt ’s hands for 
reproduction, and the illustrations of the present paper are the 
results. These plates very fairly represent the original negatives. 
One of them is on plain, one on enamelled paper. The latter more 
closely resembles an albumen print from the negative than the 
former does, but the enamelled paper has a certain glare, and I 
observe that it easily cracks if crumpled. It is a question how 
VOL. VIII. K 
