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boiling water。 The mass left； after the fluid has
wholly exhaled； must be well powdered； and when
wanted for use； may be converted into ink by the
addition of water。〃
* * * * * * * *
〃Ten parts of logwood are to be exhausted with
eighty of boiling water。 To the solution one thousandth
of its weight of yellow chromate of potash
is to be added gradually。 The liquid turns
brown and at last blue…black。 No gum is needed；
and the ink is not removed by soaking in water。
Chemical Gazette； London （1850）。〃
* * * * * * * *
〃Shellac； 2 oz。； borax； 1 oz。； distilled or rain
water； 18 oz。 Boil the whole in a closely covered
tin vessel； stirring it occasionally with a glass rod
until the mixture has become homogeneous； filter
when cold； and mix the fluid solution with an ounce
of mucilage or gum arabic prepared by dissolving
1 oz。 of gum in 2 oz。 of water； and add pulverized indigo
and lampblack ad libitum。 Boil the whole
again in a covered vessel； and stir the fluid well to
effect the complete solution and admixture of the
gum arabic。 Stir it occasionally while it is cooling；
and after it has remained undisturbed for two
or three hours； that the excess of indigo and lamp…
black may subside； bottle it for use。 The above
ink for documentary purposes is invaluable； being
under all ordinary circumstances； indestructible。
It is also particularly well adapted for the use of
the laboratory。 Five drops of creosote added to a
pint of ordinary ink will effectually prevent its becoming
mouldy。〃
* * * * * * * *
〃In November； 1854； Mr。 Grace Calvert read a
paper before the London Society of Arts in which
he said that he hoped before long some valuable
dyeing substances other than carbo…azotic acid
would be prepared from coal tar。
〃In another paper read before the same society
in 1858 he said： 'This expectation has now been
fulfilled。 Messrs。 Perkins and Church have obtained
several blue coloring substances from the
alkaloids of coal tar； and one from naphthalene。'
Also that himself and Mr。 Charles Lowe had succeeded
in obtaining coal tar products yielding colors
of a beautiful pink； red； violet； purple； and
chocolate。 （These were not soluble in water）。〃
* * * * * * * *
〃Among vegetable substances useful in the arts
is one that has long been known in New Grenada
under the name of the ink…plant； as furnishing a
juice which can be used in writing without previous
preparation。 Characters traced with this substance
have a reddish color at first； which turns to a deep
black in a few hours。 This juice is said to be
really less liable to thicken than ordinary ink； and
not to corrode steel pens。 It resists the action of
water； and is practically indelible。 The plant is
known as coryaria thymifolia。〃
* * * * * * * *
〃Desormeaux recommends that the sulphate of
iron be calcined to whiteness； coarse brown sugar
instead of sugar candy； 1/4 oz。 acetate of copper；
instead of one ounce of the sulphate； and a drop
or two of creosote or essential oil of cloves to prevent
moulding。〃 （See Ribaucourt receipt； p。 194。）
* * * * * * * *
〃Mr。 John Spiller communicated to the London
Chemical News （1861） a paper on the employment
of carbon as a means of permanent record。 The
imperishable nature of carbon； in its various forms
of lamp…black； ivory…black； wood…charcoal； and
graphite or black lead； holds out much greater
promise of being usefully employed in the manufacture
of a permanent writing material； since； for
this substance； in its elementary condition and at
ordinary temperatures； there exists no solvent nor
chemical reagent capable of affecting its alteration。
〃The suggestion relative to the mode of applying
carbon to these purposes； which it is intended
more particularly now to enunciate； depends on
the fact of the separation of carbon from organic
compounds rich in that element； sugar； gum； etc。；
by the combined operation of heat and of chemical
reagents； such as sulphuric and phosphoric acids；
which exert a decomposing action in the same
direction； and by such means to effect the deposition
of the carbon within the pores of the
paper by a process of development to be performed
after the fluid writing ink has been to a certain
extent absorbed into its substancea system of
formation by which a considerable amount of resistance；
both to chemical and external influences；
appears to be secured。 An ink of the following
composition has been made the subject of experiment：
〃Concentrated sulphuric acid；
deeply colored with indigo 。。。。。。。。。。 1 fluid ounce。
Water； 。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。 6 〃 〃
Loaf Sugar；。。。。。。。。。。。。。。。。。。。。。。。。。。 1 ounce； troy。
Strong mucilage of gum…arabic
2 to 3 fluid ounces。
〃Writing traced with a quill or gold pen dipped
in this ink dries to a pale blue color； but if now a
heated iron be passed over its surface； or the page
of manuscript be held near a fire； the writing will
quickly assume a jet black appearance； resulting
from the carbonization of the sugar by a warm
acid； and will have become so firmly engrafted
into the substance of the paper as to oppose considerable
difficulty to its removal or erasure by a
knife。 On account of the depth to which the
written characters usually penetrate； the sheets of
paper selected for use should be of the thickest
make； and good white cartridge paper； or that
known as 'cream laid；' preferred to such as are
colored blue with ultramarine； for； in the latter
case； a bleached halo is frequently perceptible
around the outlines of the letters； indicating the
partial destruction of the coloring matter by the
lateral action of the acid。
〃The writing produced in this manner seems indelible；
it resists the action of 〃salts of lemon；〃
and of oxalic； tartaric； and diluted hydrochloric
acids； agents which render nearly illegible the traces
of ordinary black writing ink； neither do alkaline
solutions exert any appreciable action on the carbon
ink。 This material possesses； therefore； many
advantageous qualities which would recommend its
adoption in cases where the question of permanence
is of paramount importance。 But it must； on the
other hand； be allowed that such an ink； in its
present form； would but inefficiently fulfil many of
the requirements necessary to bring it into common
use。 The peculiar method of development rendering
the application of heat imperative； and that of
a temperature somewhat above the boiling point of
water； together with the circumstance that it will
be found impossible with a thin sheet of paper to
write on both sides； must certainly be counted
among its more prominent disadvantages。〃
* * * * * * * *
〃Fire…proof ink for writing or printing on
in