Examination of the cross-sections has shown that in the earlier phase he used exclusively cobalt blue, available from 1802, his habitual choice during the 1870's and early 1880's, but in finishing and revising the composition he used only artificial ultramarine which came in use in the 1870s.
A common misconception with this is that nits and lice are the same thing. In fact this is not the case, the truth is: Lice are the tiny grey or brown insects that are found in the hair. The lice are about the size of a small seed (i.e. Sesame seed) and cling to the hair staying close to the scalp which they live off.
Use nit combs or cat flea combs to remove the lice and eggs. Because eggs can hatch for up to 10 days after they are laid, comb hair daily for two weeks after you find the last live head lice, to remove any young that have emerged.dult head lice are about 1/8 inch long, grayish, flattened, and wingless. Their legs are claw-like, designed to hold onto hair. These lice excrete partially digested blood which can appear as 'black dandruff'. Lice eggs, commonly referred to as nits, are whitish, oval and the size of a pinhead (1/30 inch long).