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less rapidly by peroxide of hydrogen than by chlorine. Tessie du Motay and 
Marechal mention it as one of the agents which they propose for bleaching 
tissues, which, after treatment with permanganate of potash, they recommend 
to be steeped in a solution of peroxide of hydrogen. But it had been much 
earlier applied as a bleaching-agent by Thenard himself for a particular pur- 
pose — namel}, for restoring old oil-paintings and drawings. White-lead in 
old paintings, which has become blackened by the gradual aCtion of sulphuretted 
hydrogen, is converted into sulphate of lead by dilute solutions of peroxide of 
hydrogen, and thus restored to its primitive colour. A fine drawing by Raffaelle, 
with superimposed white which had become spotted with black, was completely 
cleansed by a solution which contained at most five or six times its volume of 
available oxygen, and the paper did not suffer. A peculiar application of this 
bleaching-agent has been made public by A. v. Schrotter and others. During 
the last few years bottles labelled “ Eau de Fontaine de Jouvence, golden,” 
and containing about 140 c.c. of a colourless liquid, have been sold by per- 
fumers in great cities : to them, it appears, is due that offensive blonde shade 
of hair which holds an intermediate place between ash-grey and bright yellow, 
and attracts the attention of the spectators and the curiosity of observers by 
its piquante unnaturalness. This secret nostrum is merely a solution of hy- 
drogen peroxide made stable by copious dilution, and by addition of a small 
quantity of acid — apparently nitric acid. A bottle costing 20 francs yields the 
purchaser 2'5 to 4 grms. of this substance in solution, and effects its purpose 
completely, though slowly, within four to six days, thus strikingly illustrating 
the great efficacy of peroxide of hydrogen. This would not be the first body 
whose industrial application commenced with trifles and gradually reached an 
unimagined extension. Nitrate of silver served first the vanity of the world 
as a hair dye long before its applications in photography. Schrotter very 
rightly expresses the wish that peroxide of hydrogen might be generally ac- 
cessible at a moderate price. That for medicinal purposes it is preferable to 
oxygen and ozone is manifest. Whilst ozone only bleaches ivory in the 
strongest sunshine of summer, there is no doubt but that peroxide of hydrogen 
would answer the same purpose even in the absence of light. 
Mr. Thomas Routledge, of Sunderland, who in 1860 was the only paper- 
manufaCturer using esparto, the supply of which is now decreasing, has 
called the attention of paper-manufaCturers to the probable advantages that 
would be derived from the employment of bamboo as a cheap and useful 
paper-making material. 
Up to 1840 mirrors were silvered exclusively by means of an amalgam of 
tin — a process most destructive to the workmen employed. An important step 
was effected by an English chemist, Drayton, who conceived the idea of coating 
mirrors with a thin layer of silver, obtained by reducing an ammoniacal solu- 
tion of nitrate of silver by means of highly oxidisable essential oils. This 
process was subsequently modified by several chemists, but only became 
really practical when M. Petitjean substituted tartaric acid for the reducing 
agents formerly employed. The glass to be silvered is laid upon a horizontal 
cast-iron table heated to 40°. The surface is well cleaned, and solutions of 
silver and of tartaric acid, suitably diluted, are poured upon it. The liquid, in 
consequence of a well-known effeCt of capillarity, does not flow over the edges, 
forming a layer of some m.m. in thickness. In twenty minutes the silver 
begins to be deposited on the glass, and in an hour and a quarter the process 
is complete. The liquid is poured off, the glass washed with distilled water, 
dried, and covered with a varnish to preserve the silver from friction. The 
advantages are evident. Mercury with its sanitary evils is suppressed ; there 
is a gain in point of cost, as 4 to 5 grms. of silver, costing about 1 franc, suffice 
for 1 square metre, which, under the old system, would require 700 grms. of 
tin and the same weight of mercury. A few hours suffice to finish a glass on 
the new system, whilst the old process required twelve days as a minimum. 
On the other hand, the glasses thus silvered have a more yellowish tint ; por- 
tions of the pellicle of silver sometimes become detached, especially if exposed 
to the direct action of the sun, and despite the protecting varnish the silver is 
