z vi 
so General Notes. 
give the white a leathery consistency. After the piece of 
has been thoroughly saturated with colored white and sprin 
freely with the coloring-powder, as before described, it is spread 
out on a clean glass plate and pressed down so as to leave m 
‘ air-bubbles between it and the glass. It is then left to dya 
ordinary room temperature. When completely dry it is removed 
from the glass and covered with a thin collodion solution. AS 
soon as the collodion coat is dry the tablet is thrown into bor 
ing water and kept below the surface by weighting for fifteen 
minutes. Black tablets colored with lampblack should always 
be made in this way, as they generally appear flecked whet 
made by the first method. y 
The Reduction of Chromic Solutions in Animal Tiss 
corrected by Reoxidation with H,O,.—It is well known 
ing manner: “If a solution of chromic acid 
potassium be mixed with a solution of H,O,, a deep gre? 
“Tf the sections, at the moment when the bront 
color appears, are removed from the solution and, 
washed, the color of the chromic chromate, which 15 
portant for many histological details, remains fixed. 
= 
i * Archiv f. mik, Anat., xxx., H. 1, p. 47, 1887; Of Monatsheft f. prakt. 
i. p. 31. ae 
