1892.] Microscopy. 631 
Mylodon. It has less lime and more silica. In their other chemical 
constituents they are without any great difference. Of lime the bone 
of the Mylodon has 30.48%, while that of man has but 25.88%. Of 
silica the Mylodon has 3.71%, while man has 22.59%. I am well aware 
of the ordinary uncertainty of this test when applied to specimens 
from different localities and subjected to different conditions; but in 
the present case no such differences exist. The bones were all 
encased in the same stratum of blue clay, and were subjected prac- 
tically to the same conditions and surroundings. As one swallow does 
not make a summer so the discovery of one specimen does not prove 
the antiquity of man; but it is to be remarked that upon each dis- 
covery and in almost every investigation the evidence found points 
towards higher antiquity of man and tends to show the occupation of 
the earth by prehistoric man to be more and more extensive. This 
discovery is simply a fact to be put down to the credit of the high 
antiquity of man. We should proceed in the same direction to dis- 
cover other evidences, to investigate the value of those already found ; 
and as they accumulate, each one or all together should be given their 
fair value, in the endeavor to arrive at a truthful conclusion independ- 
ent of a priori theory or preconceived idea. 
MICROSCOPY. 
Methods of Decalcification. Continued.—V. von Ebener’s 
Hydrochloric Acid and Sodium Chloride Method?—To avoid the swell- 
ing caused by hydrochloric acid the author gives she following for- 
mula: 
Hydrochloric acid 2.5 parts. 
We NINE oes eee as ee 500. 4 
Sodium chloride bo a a 
Distilled water 100. < * 
The fixed and hardened tissue is placed in this solution, which is 
daily strengthened by the addition of a small quantity of acid; when 
decalcified the preparations are washed in a half saturated aqueous 
solution of sodium chloride; when the solution shows an acid reaction 
it is neutralized by the addition of ammonia; this is repeated until 
the acid is entirely removed. 
1Edited by C. O. Whitman, Clark University, Worcester, Mass. 
*Wien. Sitzungsber., 1875, Zeit. f. wiss. Mikros., Bd. viii, p. 6, 1891. 
