16 
I 
has described the combinations in his 
suites of colours, which are very correct ; 
these are given, and the same plan fol- 
lowed, in describing those colours which 
are added in this series. The method of 
distinguishing colours, their shades, or 
varieties, is thus described by Werner : 
" Suppose we have a variety of colour, 
which we wish to refer to its characteris- 
tic colour, and also to the variety under 
which it should be arranged, we first 
compare it with the principal colours, to 
discover to which of them it belongs, 
which, in this instance, we find to be 
green. The next step is to discover to 
which of the varieties of green in the sys- 
