PAINTING. 
different; neverthelefs, for white paint, the oil of caraways 
is to be preferred, becaufe colourlefs. The commoneft 
oils may be ufed for painting with the ochres. The oil, 
when mixed-in with the milk and lime, dilappears, and is 
totally dilfolved by the lime, with which it forms a calca¬ 
reous foap. 
The Spanifh-white.is to be crumbled, or gently fpread 
on the furface of the fluid, which it gradually imbibes, 
and at laft finks ; at this period it muff be well ftirred-in. 
This paint may be coloured like diftempe’r (or (ize colour), 
with levigated charcoal, yellow ochre, &c. and it is ufed 
in the fame manner. 
The quantity here prefcribed is fufficient for the firft 
coat of fix. toiles, or 27 fquare yards Englifh. The price 
of this quantity amounts to nine lols, which reduces the 
price of the fquare toife to one fol fix deniers, or three 
halfpence Englilh. 
One of the properties of this paint is, that it will keep 
for whole months, and requires neither time nor fire ; in 
ten minutes we may prepare enough of it to paint a whole 
houfe. Another advantage is, that one may fleep in a 
chamber the night after it has been painted ; for the milk- 
diftemper paint dries in the fpace of an hour, and the oil 
which enters into its compofition lofes its fmell and cha¬ 
racter of oil by its combination with the lime, which 
converts it into a true foap; the fmell of this colour, 
when frefh laid-on, is like that of a foap-ley, or like that 
of a place in which linen is bleached. A fmgle coating 
is fufficient for places that have already been painted. It 
is not neceffary to lay-on two, unlefs where greafe-fpots 
repel the firft coating; thefe fiiould be removed by waffl¬ 
ing them with ffrong lime-water, or a ley of foap, or 
fcraped off. New wood requires two coatings. One coat¬ 
ing is fufficient for a ftaircafe, paff'age, or ceiling. 
To give this paint a greater degree of lolidity, that it 
may be employed as a fubftitute for oil-paint, the author 
adds to the proportions of the paint for out-door works, 
of flaked-lime, oil, and white Burgundy pitch, each two 
ounces. The pitch is to be melted with a gentle heat in 
the oil, and then added to the fmooth mixture of the milk 
and lime. In- cold W'eather this mixture is to be warmed, 
that it may not occafion too-fpeedy cooling of the pitch, 
and to facilitate its union with the milk of lime. This 
paint, it is laid, has fome analogy with that known by 
the name of encauftic. It has been employed, the author 
informs us, for outfide fhutters formerly painted with 
oil; and is preferable to painting with lead objedts that 
are expofed to putrid exhalations, which are apt to blacken 
paint compofed of metallic matters, efpecially of lead. 
M. Devaux recommends this kind of paint as a fubfti¬ 
tute for. common white-waffi, in lime-whiting (as it is 
called) the wards of hofpitals, and the infefted cottages of 
the fick. “ As lime (the author obferves) enters into the 
compofition of my milk-paint, it may be made the bale 
of it, by fubftituting it inftead of the Spaniffi-wdiite. The 
painting will become ftill cheaper by this fubftitution, on 
account of the cheapnefs of the lime, lo that the toife of 
the painting.will coif only five centimes : as to the labour, 
there can be no want of hands in buildings where great 
numbers of individuals are collected together, and where 
every thing ought to be conduced as economically as 
pofiible. 
“ But of what advantage, it may be objected, is the 
addition of milk and of oil ? It is not by a chemift that 
this objection will be made; however this is our anfwer 
to it: The addition is made becaufe lime has no adhelion 
to the walls ; it cannot be applied in a thick layer; and 
the flighted contadf caufes it to come oft', on which ac¬ 
count. walls whitewalhed in the common way foil the 
clothes that come in contaft with them. The cafe- 
ous part of milk, the addition of the oil, which forms a 
faponaceous fubftance with the iime, afford, on the con¬ 
trary, after the evaporation of the moifture, a layer that 
poffefi'es denfity and cohefion, and is capable of receiving 
thicknefs; it is a coating, in fome meafure varnifhed, 
which annihilates the porofity of done, plafter, brick, or 
wood; and from which we may wipe off the duft without 
laying bare the place which has been painted. 
“ Milk-painting affords another advantage, which I 
have not mentioned in my memoir ; namely, that of check¬ 
ing the nitrification of the walls, which is accelerated by 
painting in difternper. In faCt, glue is an animal fub¬ 
ftance, of which one of the conftituent principles is azot ; 
now the decompolition of the glue extricates tips azot, 
which is alfo one of the conftituent principles of the nitric 
acid, and enables it to combine with the oxygen, with 
which it forms this acid. As milk-painting produces no 
extrication of azot, one of the aliments of the nitrifica¬ 
tion is removed. Morever, this painting Hops up the 
pores of the ftone, and interpofes itfelf between the walls 
and the nitrifying aCtion. 
“ Supported by the theory which I have juft explained, 
by the authority of two of our firft chemifts, Fourcroy 
and Deyeux, to whom I have fubmitted my opinion, and, 
laftly, by my own experience, I think myfelf juftified in 
recommending to the adminiftrators of hofpitals, to adopt 
the rejinous milk-painting (always fubftituting lime in the 
place of Spanifh-white), as the moft efficacious, and at the 
fame time the moft economical, means of deltroying the 
mephitifation of the walls, and preventing it for the 
future.” 
Paints prepared from Fish-Oil. 
In the Tranf. of the Society of Arts for 1805, a method 
is propofed by Mr. Vanherman, of Golden-fquare, for 
making cheap and durable paints with fifh-oil. Fonthis 
communication, Mr. V. received the filver medal and 
twenty guineas. 
The paints thus prepared, befide their cheapnefs, are 
not fubjeCt to blifter or peel off by expofure to the weather. 
They may be manufactured of any colour, and laid-on by 
ordinary labourers. The price of fome of them is fo low 
as twopence, and the higheft does not exceed threepence, 
per pound, in a ftate fit for ufe. The author adds, that 
white-lead ground with prepared fifh-oil, and thinned 
with linfeed-oil, furpafl'es any white hitherto employed 
for refilling all weathers, and retaining its whitenefs. 
The following is an account of his proceffes : 
To refine one Ton of Cod, Whale, or Seal, Oil, for Painting; 
with the Cofi attending it. 
One ton of fifh-oil, or 252 gallons, 
32 gallons of vinegar, at 2s. per gallon, 
12 lbs. litharge, at 5d. per lb. 
12 lbs. white copperas, at 6d. ditto, 
12 gallons of linfeed-oil, at 4s. 6d. per gallon,. 2 14 o 
2 gallons of fpirits of turpentine, at 8s, ditto, o 16 o 
/43 5 o 
252 gallons of fifh-oil, 
12 ditto linfeed-oil, 
2 ditto fpirit of turpentine, 
32 ditto vinegar. 
298 gallons, worth 4s. 6d. per gallon. 
Which produces £67 1 o 
DeduCt the expenfe 43 5 o 
£23, 16 o profit. 
To prepare the Vinegar for the Oil. —Into a calk which 
will contain about forty gallons, put 32 gallons of good 
common vinegar; add to this 12 pounds of litharge, and 
12 pounds of white copperas in powder; bung-up the 
veil'd,, and ffiake and roll it well twice a-day for a week ; 
when it will be fit to put into a ton of whale, cod, or feal, 
oil; (but the Southern-whale oil is to be preferred, on 
account of its good colour, and little or no fmell.) Shake 
and mix all together, when it may fettle until the next 
day; 
£36 o o 
340 
050 
060 
