THE MICROSCOPE. 223 
that by varying the conditions, through which each fat is made to 
pass in preparing it for market, genuine butter may be made to 
asssume the appearance described by Dr. Taylor as specific for 
other fats, and Vice Versa. 
Passing to third the part of Dr. Taylor’s method, the speaker 
in detail the microscopical appearance which the doctor claimed gave 
distinguished true butter from all other fats, viz. a globular crystal, 
which under the polarizing apparatus alone, shows a black St. An- 
drew’s cross, and which, when a selenite is used, gives a display 
of colors with the cross in faint outline. Secondary crystals, of a 
rosette form, are also occasionally seen. These appearances are, 
according to Dr. Taylor, never seen in any other fats. The speaker 
stated that he had made three sets of experiments to test this state- 
ment of Dr. Taylor’s, using pure creamery butter, made in the in- 
stitution with which he is connected, (the Ohio Sate Agricultural Ex- 
perimental Station) oleo-oil and lard, and the results fully bore out 
Dr. Taylor’s announced discoveries. Pure butter, the oleo-oil and 
the lard, each produced its own distinctive crystalline forms, as de- 
scribed and figured by Dr. Taylor, and if a test to distinguish pure 
butter from pure lard or pure oleo were wanted, nothing could be 
better. It is manifest, however, that no such test is needed, since 
taste, smell and sight serve the purpose. What is wanted is a test 
that will tell a mixture of any of these fats with butter, and this, 
said the speaker, Dr. Taylor’s test signally fails to do. Whenever 
a mixture of these fats is made with butter, and the resultant mass 
is studied under the microscope, as described by Dr. Taylor, it will 
be found that the crystals of the adulterants unite with the butter 
crystals and form globular crystals which behave in all respects ex- 
actly like those obtained from pure butter alone. Prof. Weber de- 
tailed a large number of experiments made by him and all of 
which prove this fact. But more than this, the speaker stated that 
he had, by varying the treatment, succeeded in obtaining from 
mixtures of oleo-oil and lard, and from oleo alone, globular crys- 
tals that could in no respect be differentiated from those obtained 
from pure butter. 
In conclusion Prof. Weber stated that he had undertaken his 
experiments with no prejudice to Dr. Taylor, and with the simple 
desire of arriving at the truth alone. He had come to the conclu- 
sion—the only one that could be drawn from the results obtained 
