Purpose of Printing therefrom.
Year: 1885

page_text: Purpose of Printing therefrom.
I, HORACE MACLURE of 97 Queen Victoria Street in the City of London
Lithographer do hereby declare the nature of said Invention for IMPROVEMENTS
IN THE TREATMENT OF LITHOGRAPHIC STONES FOR THE PURPOSE OF PRINTING
THEREFROM to be as follows:-
This Invention relates to an improved method of treating Lithographic stones
after the drawing or transfer has been made thereon and it consists in the employ-
ment as a substitute for the acids now employed of a solution of Hydrochloric
Acid this acid being applied to the stones in the manner now well understood
when a solution of Nitric acid is used. The stone so prepared is then much
improved by having a solution of Nutgalls or of other astringent material or
element applied to its surface subsequent to the treatment with the before
mentioned acid. Stones which have been treated with Nitric Acid in the ordinary
manner are also much improved in sharpness and brilliancy by the treatment with
Nutgall or other astringent material,
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Horace Maclure.

page_text: Purpose of Printing therefrom.
I, HORACE MACLURE of 97 Queen Victoria Street in the City of London
Lithographer do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
My Invention relates to an improved method of treating lithographic Stones
after the Drawing or transfer has been made thereon and it consists in the employ-
ment as a substitute for the acids now employed. of a solution of hydro-chloric
acid which may be applied to the stones in the same manner as that in which nitric
acid is applied. The stone so prepared is then much improved by having a solution
of nut galls or of other astringent material applied to its surface subsequent to the
treatment with the before mentioned acid. Stones which have been treated with
nitric acid in the ordinary manner are also much improved in sharpness and
brilliancy by this treatment with nut gall or other astringent material.
I have found that good results are obtained by using a solution of one ounce of
hydrochloric acid to one pint of gum water but the strength of the said solution
must depend upon the strength of the work upon the stone as when very fine lines
are in the design a weaker solution is necessary than otherwise is the case.
This solution may best be applied to the stone in the same way as nitric acid is
at present applied. The nut-gall or other astringent material is best applied by
preparing a solution and twelve nut galls to one pint of water will give a suitable
strength of the astringent solution, but I do not limit myself to the precise
strengths of the solutions as hereinbefore stated nor to any particular ways of
applying them to the stone.
Having now particularly described and ascertained the nature of this Inven-
tion and in what manner the same is to be performed I declare that what
I claim is
First. In the preparation of lithographic stones the employment of hydrochloric
acid substantially as hereinbefore described.
Second. In the preparation of lithographic stones, the employment of nutgalls
or other astringent material substantially as hereinbefore described.
Third. In the preparation of lithographic stones the employment first of hydro-
chloric acid and subsequently of nut galls or other astringent materials substantially
as hereinbefore described.
th: 1
100-