Ixii REPORT—1858. 
Since Niépce, Herschel, Fox Talbot, and Daguerre laid the foundations 
of Photography, year by year some improvement is made, some advance 
achieved, in this most subtle application and combination of discoveries in 
Photicity, Electricity, Chemistry, and Magnetism. 
Last year M. Poiteven’s production of plates in relief, for the purpose dof 
engraving by the action of light alone, was cited as the latest marvel of 
photography. This year has witnessed photographie printing in carbon. 
M. Pretschi’s method is as follows :— 
“« A photograph or engraving is placed on the prepared plate, and a nega- 
tive taken in sun-light. The glass is then placed in water with a little 
alcohol, and the darkened parts are rendered soluble, while the other parts 
are insoluble, so that in a few minutes we have a picture represented not 
only by light and shadow, but by the unequal thickness of the gelatine on 
the glass. When the plate is dry, soft gutta-percha is pressed upon the 
picture till it hardens. The gutta-percha has consequently an image the 
reverse of the first. After rubbing it over with bronze powder or black- 
lead, it is placed in a solution of sulphate of copper, and an electrotype plate 
taken from it, in the usual way, with a voltaic battery. From this plate 
others can be readily taken, and, as in ordinary copperplate printing, thou- 
sands of copies can be thrown off. ‘By this process,’ says Mr. Hunt, ‘pic- 
tures, in which the most delicate details are very faithfully preserved, and 
the nice gradations in light and shadow maintained in all their beauty, are 
now printed from the electrotype plate, obtained from the photograph. The 
process of photo-galvanography is evidently destined to take a very high 
position as a means of preserving the beauties of nature and art.’ ” 
M. Niépce de St. Victor has succeeded in reproducing the colour of the 
original on metallic plates; though he cannot fix it. Unfortunately these 
lovely ‘heliochromes’ vanish like the breath from the mirror. 
M. Delarue has obtained photographs of the moon in which the details of 
its illuminated surface are well defined—the cone in ‘ Tycho,’ the double 
cone in ‘ Copernicus,’ and even the ridge of ‘ Aristarchus.’ A photograph 
of the planet Jupiter has been obtained in which the belts are very well 
marked and the satellites distinct. 
The portrait of a 13-inch shell has been secured while in full flight, a few 
feet after it left the mortar; and, in effecting this, Mr. Scaife has obtained 
a representation of phenomena in the development of the smoke too trans- 
itory for the eye to ascertain when they occur. The photographic eye is, in 
fact, more sensitive than the living one: it can receive and register impres- 
sions too fine for human vision, until made visible by increased light and 
developing agents. Hence, photography may superadd a new defining fune- 
tion to the highest attainable telescopic power. 
Photography is now a constant and indispensable servant in certain im- 
portant meteorological records. Applied periodically to living plants, photo- 
graphy supplies the botanist with the easiest and best data for judging of 
