89 
yielding a sublimate of yellow lustrous scales and needles. 
It is almost insoluble in boiling water, but dissolves easily 
in concentrated sulphuric acid, even in the cold, giving a 
cherry-red solution. It does not dissolve sensibly in caustic 
potash lye in the cold, but on boiling a bright cherry-red 
solution is obtained, which on cooling deposits dark red 
crystalline masses. The solution shows no trace of absorp- 
tion bands, but onl/ a general obscuration of the green part 
of the spectrum, and in this respect differs widely from the 
alkaline solutions of alizarine, which exhibit such very 
characteristic absorption bands. The solution in concen- 
trated sulphuric acid does, however, show an absorption 
band on the border of the green and blue, just like a solution 
of anthraflavic acid in the same menstruum, but far less 
distinctly than the latter, on account of the much greater 
obscuration of the parts of the spectrum adjacent to the 
band. On adding alcoholic potash solution to an alcoholic 
solution of methyl-alizarine the potassium compound is 
deposited in dark red * needles, arranged in star-shaped 
masses. The sodium compound, prepared in the same way, 
crystallises in small light red needles. A watery solution 
of the potassium compound gives with chloride of barium a 
red flocpulent precipitate. The alcoholic solution of methyl- 
alizarine gives no precipitate with acetate of lead. When 
treated with boiling nitric acid methyl-alizarine is dissolved 
and decomposed, and the solution on evaporation leaves a 
white crystalline residue, probably of phthalic acid. Methyl- 
alizarine undergoes no change when treated with strong 
caustic potash lye, even at the boiling temperature. It is 
only when fusing hydrate of potash is employed that de- 
composition takes place. If the operation be carefully con- 
ducted there is obtained, on the addition of water to the 
fused mass, a violet -coloured solution, which shows the 
absorption bands of alizarine very distinctly. There is no 
doubt, therefore, that by the more energetic action of the 
