360 
THE YOUNG SCIENTIST. 
the way of attaining perfect success in 
color-making is the adjustment of the 
flux. Indeed, it is scarcely too much to 
say that this c'onstitutes the nicest and 
most delicate part of the whole process. 
1. The flux should be suited to the pig- 
ment as regards the composition of the 
latter; 2, it should be proportionate in 
quantity to the pigment according to its 
nature; (3) it should uniformly cohere 
with the glaze of the ware beneath ; and, 
4, the different fluxes, whatever their 
composition, should always vitrefy at one 
uniform temperature. The degree of 
nicety to which this adaptation must be 
carried will be appreciated when it is 
stated that an excess in one of the ingre- 
dients only amounting to between '3 and 
•4 per cent, of the flux may destroy the 
color. 
Speaking generally, then, it is not to 
the amateur's interest to endeavor to be 
his own color-maker. To expend dollars 
on a furnace when for as many dimes 
he may get as much color as will in the 
ordinary way last him for some years, 
will not jpay. Of course there are a few 
colors which may be made at home, but 
even as to these I am inclined to doubt 
that the domestic manufacture of them 
would be profitable except as a pastime, 
seeing that those most easily made are 
among the cheapest. There are published 
recipes on the subject which may be con- 
sulted by the amateur desirous of trying 
his hand in this line ; but apart from the 
consideration that some are scarcely in- 
telligible in modern strictness, and others 
are known to be incorrect, I think I have 
said enough to show that, except in a few 
cases, lejeu ne vaut pas la chandelle. 
36. EmploymeMt of Different Makes in one 
Painting Unadvisable. — The point (4) no- 
ticed in the last paragraph but one de- 
mands further attention as bearing great- 
ly on a very practical consideration. It is 
essential to the *' finish " of a picture that 
after the firing all the colors should be 
equally glossy, and should have equally 
and completely adhered to the glaze of tlie 
ware. This end, so far as the painter is con- 
cerned, is, as a rule, to be attained by the 
use in any one painting of the colors of 
only one maker. It is the fact that there is 
one recognized standard of heat for firing 
enamel colors, and at this heat, technic- 
ally known as "rose-color" heat, the color 
should be developed in all its perfection ; 
but, unfortunately, it is not always the 
case that colors of different makers will 
fire properly at one heat. In these cir- 
cumstances it is with pleasure and confi- 
dence that I recommend for general use 
the colors w^hich I now employ, after an 
experience of those of three other mak- 
ers, viz., those of the manufacture of 
Messrs. Hancock & Sons, of Worcester, 
Eng. Of these I cannot speak too highly. 
The grinding of them is complete, they 
do not concrete, they all vitrefy and de- 
velop equally, and, a not unimportant 
point as regards price, the quantity in the 
No. 2 sized bottles compares very favor- 
ably with that offered by other makers. 
37. Dry v. Moist Colors.— These are now 
issued in the forms of dry powder, oil me- 
dium i^aste, and moist water-color. The 
relative worth of dry and oil-paste color 
has been much debated, but it is sufficient 
to say, that while it must be conceded 
that there is on first opening a fresh tube 
of color mixed with an oil medium, some 
advantage in respect of convenience, it is 
undeniable that in every other respect 
the advantage is on the side of the pow- 
der color. I cannot do better than give 
some of the "reasons" of the firm for 
originally deciding upon powder color : — 
"I. Professionals know from experi- 
ence that the sooner colors are used and 
fired after mixing with oils, etc., the 
brighter and better they will be when 
fired. 
" II. Dry colors may be mixed thick or 
thin as they are required; whereas, if 
tubes are used and the color is too thin, 
it is difficult to make it stififer for any par- 
ticular purpose," witliout at the same 
time running the risk of having the mix- 
ture too fat. [A. de Y.) 
"III. Colors kept in tubes are apt to 
separate from their oils, if kept any 
length of time, thereby necessitating the 
trouble of re-mixing with a palette-knife 
(as much trouble as mixing in the first in- 
stance). 
"IV. There is considerable uncertainty 
in producing,> by mixture of various tube 
