768 
of the extract in c.c. and c the standard percentage of the tint, then 
cb 
100a 
if 1 gr. of the substance was completely extracted to 1 cc. of ether- 
extract, the content expresses how many times this tint is stronger 
than our standard-tint. 
Animal tissues are minced up and divided into two portions. Of 
one of them a water determination is made, by drying it with 
dried seasand on the waterbath to a constant weight. 
The other portion is rubbed with alcohol and ether and, as in 
the case of plants, the content is determined. The content of animal 
tissues was generally determined for 1 gr. dry substance. With fat 
a fat-determination is substituted for a water determination, so 
that in that case the content is determined for 1 grm. of pure fat. 
The determination of the lipochrome-content of carotin-like and 
xanthophyll-like pigment in some parts of plants yielded the following 
result (the values found represent quanta of pigment to 100 grms. 
of moist substance, the pigment solved in 100 cc. of ether. (See 
table I). 
In making these determinations we used only a rather rough 
method. Besides the lipochrome pigment the solutions also contained 
all sorts of impurities. Moreover, if in our experimentation, we start 
from small quantities of material, traces of lipochrome will be 
unobserved. If, in starting from 10 ecc. of cow’s serum, we find 
3 carotin and 0 xanthophyll, it is very well possible that, when 
working with large quantities of serum, traces of xanthophyll might 
still have been detected. 
While performing these determinations, we have assumed that 
both groups of lipochrome (carotin and xanthophyll) have in the 
same concentration the same colour and intensity of colour, which 
is regularly diminished through dilution. According to WILLSTATTER’s 
experience this statement is not right. With the considerable dilu- 
tions, used by us, we deemed it justifiable to neglect this error. 
The values found are mean values, those of the several samples of 
the same substance often differ very much. 
As said in a previous communication, we mean by carotin and 
xanthophyll the pigments that have a greater affinity either for 
petroleum-ether, or for methylalcohol, being well aware that this 
group may comprise various substances. 
In order to ascertain the influence of diet upon the serum-lipo- 
chrome, we determined in a dozen subjects the amount of this 
pigment first with the ordinary, mixed, hospital diet, and a second 
So we determined the tint as 
the formula for the content is 
