Tuer Microscope. 225 
microscopical examination the lard crystal may be at once de- 
tected and save further labor. 
Dr. Taylor further stated that it should be borne in mind that 
the object sought was not the presence of butter, but the presence 
of foreign fats, and that the moment they were detected by the 
microscope, the parties may be prosecuted under the butter laws of 
the District of Columbia. ; 
Dr. Taylor here stated that already seven convictions had been 
made under his testimony, and in no case had he sanctioned a 
prosecution, unless he found an abundance of lard or beef fat crys- 
tals, or other foreign fats in the substance. Dr. Taylor further said 
that the parties subjected to the prosecution, rich and poor, men 
and women, publicly acknowledged, on conviction, that they knew 
that the substance they were prosecuted for selling was oleomar- 
garine. Following this Dr. Taylor discussed the experiments of 
Prof. Weber in relation to the production of the so-called butter 
erystal by artificial means. Dr. Taylor said that Prof. Weber be- 
lieves he has by the use of salt and water in the manner described 
by him, formed or caused to be formed, butter-like crystals by 
using either oil or lard. In relation to these experiments Dr. 
Taylor stated that he had lately found that while the kidney and 
cellular tissue fats gave purely stellar crystals without a cross, 
that a sample of leaf lard, lately tested by himself, yielded stellar 
crystals with a cross, but these crystals could not be mistaken for 
butter crystals by an experienced observer, since they show dis- 
tinctly the spinous character of lard crystals. That the same result 
is obtained without the use of salt and water is shown also, in this 
connection. Dr. Taylor stated that, in point of fact, the introduc- 
tion of salt and water was not necessary to produce the cross. Dr. 
Taylor cited the number of fats that he had examined showing in 
their first stages of crystallization a globose crystal with cross, all 
without the addition of salt and water. Dr. Taylor here gave four 
illustrations upon the blackboard of four different fats whose forms 
could be seen with plain transmitted light. Following this Dr. 
Taylor threw the form of a cross on each of the illustrations, point- 
ing out the fact that notwithstanding that each was invested with 
the shadow or illusive marking of the cross, each form could still 
bé distinguished one from the other by reason of their peculiarities, 
thus showing that the presence of the cross would not alter the 
