54 REPORT—1857,. 
quinine has not been exposed to light, it produces no effect on the photographie paper. 
Other substances act as sulphate of quinine. 
The second method of rendering palpable this peculiar action of light is as follows:— 
“J take,” says M. Niépce, ‘“asheet of paper which has been kept for some time in 
complete darkness; I cover it with a photographic print taken either on glass or paper, 
and I expose them to the rays of the sun, after which I immediately carry my sheet 
back into a dark room. ‘Taking off my photographic print, I plunge my sheet of 
paper into a solution of nitrate of silver; in a very short space of time the image of 
the print appears upon it, It is only necessary to wash the sheet in water to fix 
permanently the impression thus obtained. To obtain a more perfect impression, 
and one, moreover, produced in a still shorter space of time, it is necessary that the 
sheet of paper be previously impregnated with one of those substances which possess, 
to a great degree, the faculty of absorbing light. The most efficacious is perhaps a 
solution of nitrate of urane or tartaric acid. ‘The image obtained by the medium of 
these substances is of a chestnut colour. To render it black, it may be treated with 
chloride of gold. The prints thus obtained are positives; they resist the destructive 
action of boiling cyanide of potassium, ammonia, &c.; agua regia alone destroys them. 
A slight degree of heat accelerates the above phenomena,” . 
The author has experimented with a great number of absorbing substances and 
with very varied effects. He is still occupied with these interesting researches, 
On Three New Electrotype Processes. By M. 1’ Asst Moteno. 
The first of these improved processes consisted in the employment of platina wires 
instead of copper, and of making a skeleton figure resembling roughly the outline of 
the cast sought to be obtained, by means of which, according to M. Lenoir’s process, 
busts, statues and groups can be produced in full relief by a single operation, The 
second of these consisted in M. Oudry’s process for galvanizing or coppering iron and 
east iron to any thickness required without the cyanide bath, with remarks upon its 
employment in commerce and in the navy. The process was not fully communicated, 
as it is commercially desirable to keep it a secret; but sufficient was communicated to 
show that the cyanide bath, which is not only expensive but dangerous, can be dis- 
pensed with, and the present system, according to which there was a.great waste of 
material, avoided, although the substance that was placed upon the iron to induce the 
deposit of the copper was not stated. The process essentially consists in depositing 
by electricity, copper in a pure state, to any thickness, upon articles of cast, wrought, 
or rolled iron, zine and other metals, and alloys of metals, after being coated with one 
or several coats of a composition in a liquid or semi-liquid state, serving as an isolating 
and metallizing medium. The author claims also as his invention the application to 
metallic articles, compositions, paints or varnishes of any kind to act as protective 
intermediates, before depositing on them the required thickness of copper, by means 
of the galvanic battery. The last branch of the paper treated of Messrs. Christofe 
and Bouillet’s process for strengthening electrotypes, the principle of which was to 
leave an opening in the back of the thin electrotype obtained by precipitating, and 
to put into it various little pieces of brass, which, on being melted with an oxy- 
hydrogen blast, became diffused all over the interior surface of the copper without 
injuring it in any way, and thereby imparted to it the strength of cast iron. 
On the Choice of Perennial rather than Annual Fertilizers. 
By Sir James Murray, MD. 
The author referred in the first place to the writings of Mr. S. Ferguson, in the 
‘Evening Mail,’ relative to the soluble biphosphate of lime, first applied to land near 
Belfast forty years ago. One of these mere trials, with vitriolized bones, yielded — 
luxuriant crops in June 1808. Long-continued experiments having now convinced — 
him that the soluble biphosphates were in fact too soluble, he had turned his attention 
to some combination in which the principal qualities of the manure might be conso- 
lidated, for liberation, little by little, as required by the state of the crops. He laid 
before the meeting some of the double phosphate of ammonia and magnesia, artificially — 
prepared as a fertilizer, which will remain nearly insoluble, in tanks or on lands; and 
yet by a light sprinkling of muriatic acid or common salt mixed with light dust, in 
