ts
of wine, of the strength usually sold, in a glass retort. I boil the
alcohol till the wax is completely dissolved (first taking care to place at
the end of my retort an apparatus, by means of which I can collect all the
produce of the distillation). I pour into a measure the mixture which
remains in the retort while liquid; while it is getting cool, the myricine
and the cerine harden or solidify, and the ceroleine remains alone in
solution in the alcohol. I separate this liquid by straining it through
fine linen; and by a last operation, I filter it through a paper in a glass
funnel, after having mixed with it the alcohol resulting the distillation.
I keep in reserve this liquor in a stopper-bottle, and make use of it as I
want it, after having mixed it in the following manner.

2nd. Next I dissolve, in 150 grammes of alcohol, of 36 degrees of strength,
20 grammes of iodide of ammonium (or, of potassium), 1 gramme of bromide of
ammonium or potassium, 1 gramme of fluoride of potassium or ammonium.

I then pour, drop by drop, upon about 1 gramme of fresh-made iodide of
silver a concentrated solution of cyanide of potassium, only just
sufficient to dissolve it.

I add this dissolved iodide of silver to the preceding mixture, and shake
it up: there remains, as a sediment at the bottom of the bottle, a
considerable thickness of all the above salts, which serve to saturate the
alcohol by which I replace successively the saturated which I have
extracted by degrees in the proportions below.

3rd. Having these two bottles ready, when I wish to prepare negatives, I
take about 200 grammes of the solution No. 1. of ceroleine and alcohol,
with which I mix 20 grammes of the solution No. 2.; I filter the mixture
with care, to avoid the crystals which are not dissolved, which always soil
the paper; and in a porcelain tray I make a bath, into which I lay to soak
for {383} about a quarter of an hour the papers selected and cut, five or
six at a time, till the liquor is exhausted. Taken out, hung up by the
corner, and dried, these papers, which have taken a uniform rosy tint, are
shut up free from dust, and kept dry. With regard to the sensitizing by
nitrate of silver, the bringing out of the image under the action of gallic
acid, and fixing the proof by hyposulphite of soda, I follow the usual
methods, most frequently that of Mr. Le Gray.

I add only, if I have any dissolved, 1 or 2 grammes of camphorated spirits
to 1 litre of the