362 Richards and Palmer—Antimony Tannate. 
which we used for all our experiments, and having washed by 
decantation so as to keep the gelatinous precipitate in the best 
condition for absorbing color, we treated solutions of several 
of these substances with a quantity of antimony tannate corres- 
ponding to the estimated quantity of tannin contained in the 
solution, so as to have the conditions the same as in the pre- 
vious precipitations; in one case we increased the amount of 
antimony tannate. e composition of the antimony tannate 
thus treated in the different solutions, together with the 
average composition of antimony tannate as we have already 
obtained it from tannin, sumac and nut-galls is given as 
follows: Sb. C. H. 
Per cent. Percent. Per cent. 
Sweet-fern + antimony tannate -....-.. 15°70 46°21 3°73 
Quercitron + antimony tannate -...---- 954 45°90 3°80 
Hemlock + antimony tannate--...-.. - 63°30 3°60 
Hemlock-five times the required amount 
of antimony tannate -_-_. .---..---.-- 13°40 43°40 3°90 
ANtGDytanEate . 5. 26 2s 20°00 38°21 2°86 
In the case of sweet-fern and quercitron, the results are very 
nearly those obtained by direct precipitation with tartar emetic. 
The possible reason for this will be considered later. 
We were greatly surprised by the behavior of the solution 
of hemlock-bark. In all cases after treating the solution with 
the previously prepared antimony-tannate, we precipitated the 
remaining tannin by tartar emetic as usual, and noted the 
quantity required as compared with that required for the pre- 
cipitation of tannin in the titration. The sweet-fern and quer- 
citron gave a precipitate about one-third less than that from 
the original solution. In the case of hemlock there was 
scarcely a trace of a precipitate, showing that the antimony 
tannate had dragged down or united with all the substance 
which had been supposed to be tannin. 
_ In order further to test the character of the supposed color- 
ing matter in these substances, we made a series of trials with 
mordanted yarn. - A brown-red color was obtained from hem- 
other giving on the iron stripe a faint brownish-black, corre 
