Hi everyone,
I`m ordering the stains to make up Macneals Tetrachrome, I really
like the sound of this, but Sigma sell two methylene violets one with
C.I. 52041 and one with C.I. 50206, can anyone tell me which one to
order? Bye the way , I am enjoying the saline in the microwave saga.:-)
Many thanks. Chris Goodall