NOTES AND MEMORANDA. 
379 
tLat infection from certain contagious diseases, which are common to 
man and the domestic animals, might follow.” 
The opposition which these views encountered is then referred to, 
particularly that of Professor J. W. S. Arnold, of the University of 
New York, who stated that he had examined with the microscope the 
two substances, and found their “ optical appearance alike,” which is 
accounted for, according to Mr. Michels, by the Professor having 
allowed the oleomargarine manufactory to prepare the specimen 
examined. 
A letter from the Kev. W. H. Dallinger as to a temperature of 
120° F. not being permanently injurious even to adult forms of putre- 
factive organisms is given, and Mr. Michels concludes by referring to 
“ the following independent confirmation, which was published in the 
‘ Scientific American,’ giving the result of the appearance of butter and 
oleomargarine under the microscope, by Mr. Thomas Taylor, Micro- 
scopist of the Department of Agriculture at Washington. 
Mr. Taylor reports that when pure dairy butter is viewed under 
tlie microscope, the forms consist of oil-globules, and the crystals of 
common salt ; when a specimen of oleomargarine was examined in the 
same manner, the field was speckled over with shiny particles, and it 
was demonstrated that these glistening particles were crystals of fat. 
In using a power of 250 diameters, animal tissue is seen more or less 
all over the field. One specimen of oleomargarine was highly charged 
with animal tissue and crystals of urate of magnesia, showing the fat 
used in this case to have been impure, which would seem to prove that 
the assertions made by the oleomargarine manufacturers as to the 
perfect purity of the fats used by them, are not altogether correct. 
From this it would appear that oleomargarine may be easily known 
from butter by the aid of the microscope, and that any impurities in 
the fats of which it may be composed may be readily detected.” 
Microscoipical Slides of Lichens. — The intended issue is announced 
(by Messrs. Joshua and Holmes) of a series of microscopical slides, 
illustrating the principal families, genera and sub-genera of lichens, 
to be followed by a series of specimens of lichens of which no figures 
have been published. The specimens are to be as typical as can be 
procured, and will consist of sections of the apothecia, showing all the 
various parts. 
Limits of Microscopic Visio7i. — Extracts from a letter from Professor 
Stokes, Sec. E.S., as to Fraunhofer’s formula, and one from Mr. J. 
Mayall, jun., will be found with the discussion on Dr. Pigott’s paper, 
in the ‘ Proceedings,’ at p. 389. 
Pygidium of Lnsects. — The discussion at the November meeting 
on this subject will also be found in the ‘ Proceedings,’ at p. 390. 
Baphidiophrys pallida. — A note by Professor E . Ray Lankester 
on this Rhizopod (new to this country) will be found at p. 393. 
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