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they reached a layer of tabular chalk, all pierced with large holes, forming 
so many spouts, as thick as a man’s thigh, through which water poured into 
the well with incredible velocity. While the pumps were at work to get rid 
of this water, a cylindrical revetement of bricks was built on a sort of wheel 
made of oak, and laid down flat at the bottom of the perforation by way of 
a foundation, and the intermediate space between this cylinder and the chalk 
stratum was filled with concrete, 47,000 kilos, of which were expended in 
this operation. As soon as the concrete might be considered to have set, or 
attained sufficient consistency, the brick cylinder was taken to pieces again, 
and the perforation continued to the pressure point, where a new sheet of 
water has been reached, requiring ingenious contrivances. — Vide the Artizan. 
Origin of the Diamond. — Contrary to the usual opinion that the diamond 
has been produced by the action of intense heat on carbon, Herr Goeppert 
asserts that it owes its origin to aqueous agency. His argument is based 
upon the fact that the diamond becomes black when exposed to a very high 
temperature. He considers that its Neptunian origin is proved by the fact 
that it has often on the surface impressions of grains of sand, and sometimes 
of crystals, showing that it has once been soft. 
PHOTOGRAPHY. 
Action of Light on a Bichromate associated with Organic Substances . — 
The journal of the Photographic Society — to a strange article in which we 
reluctantly called attention in our last — has returned to the charge, and in 
language scarcely less intemperate and unjustifiable than that we have 
rebuked, says, in effect, that the writer in question did not mean that Mungo 
Ponton discovered the action of light on a bichromate in connection with 
gelatine, but that M. Becquerel did so. Now, the article to which we 
condescended to reply did not contain either the name of, or the slightest 
reference to , M. Becquerel ! To quote this forgetful journalist’s own words, 
he said — “ If any fact in the history of photography be better known, more 
completely established, and less free from suspicion or doubt than another, it 
is that the discovery that organic substances combined with a bichromate 
become insoluble under the action of light was due to Mr. Mungo Ponton.” 
Could anything be more dogmatically positive ? Photographers will smile 
when we add that, as a matter of course, what the Society’s journal stated on 
this point was duly echoed in the Photographic News. In reply, we must 
remind the editors of both these publications that priority of investigation 
and priority of application are two perfectly distinct things. Although it is 
true that M. Becquerel first investigated the action of light on chromic acid 
in conjunction with organic bodies, yet the fact gives this able and talented 
experimentalist no more claim to be considered the author of Fox-Talbot’s 
special application of the principle than the old alchemists or W edgwood have 
to be considered as originating photography because the former used horn-silver 
to make labels for their bottles, and Wedgwood used nitrate of silver to 
make profiles with. 
Photography in Colours. — After the reading of Mr. Taylor’s interesting 
