46 
i)assed from the three corners over each other to the opposite sides, 
as he places them. If this would make "all possible colours," there 
would be no occasion for yelloiu and blue, which were wanted, and 
which he has been obliged to put in : here it is plain that simj)Ie 
yellow and blue must answer for themselves, even under the dulling 
influence of the general mixture *. 
There are many phamomena attending the iris like colours, which 
will now easily be reduced to some jihilosophical order for descrip- 
tion, and prevent that vague and confused uncertainty that prevails 
in many works, and which I did not dare to quote, however curious, 
as in some parts they might be above my abilities to comprehend. 
Before printing this little essay, 1 thought it proper to look at one 
■or two more works, perhaps to supersede my taking any more trouble 
about the matter; but finding nearly the same difficulties arise, I ven- 
tured to proceed. I-ndeed I was pleased that Jameson, in the eight 
fundamental colours of Werner, admits, if I take the meaning right, 
of Yellow, which he compares to ripe lemons. Blue, which he calls 
Berlin blue, commonly called Prussian blue, and Red, which is 
carmine. 
These agree with my ideas, and are exact, as I have shown ; and it 
may be universally known that these three are not naturally com- 
pounded of others, or made of mixtures, but are the bases of all possi- 
ble tints. Their not being used as such makes most of his compounds 
unnatural and absurd, as a few examples will easily show. The 
common appellations may be good, such as " snow white;" but sim- 
ply " white" might have been better, as it could properly have no 
other meaning. 
Ash gray is very indeterminate. 
Velvet black is misleading. Black must be the same on any sub- 
* It will be fuund that we can represent the primaries, yellow, red, and blue, and their 
binaries, orange, greens, and violet, in every possiblejvariety, passing among each other in 
a sketch without motions ; but we cannot represent ail the ternaries, or browns, grays 
and darks, without the motion of one of the primitives. I have got three triangles and 
quadrangles, prepared simply to show all mixtures, which will prove this. 
