492 Scientific News. [July, 
described as remarkably successful in making plain the character- 
istics of the rocks. 
OLEOMARGARINE.—Mr. John Michels has recently studied this 
substance, and drawn its appearance under the microscope. The 
abundant fat globules and occasional crystals of common salt 
which are found in real butter are almost entirely wanting, and in 
their place are found an abundance of large feathery crystals and 
of fragments of animal tissues. As the fat is merely liquified and 
set free by a heat not exceeding 120° Fahrenheit, and manipu- 
lated so as to have the general appearance of butter, any germs | 
of disease or embryos of parasites it may have contained are lia- 
ble to be preserved alive and transferred to the systems of those 
who make use of the substance. He therefore considers the 
oleomargarine, though for cooking purposes an excellent substi- 
tute for any fat previously used, to be eaten in a raw state as a 
substitute for table butter only at considerable risk. ; 
Mr ickson described atthe San Francisco Society the char- 
acter of oleomargarine cheese. Thecream fromthe milk is removed, 
_ and then liquid oleomagarine stirred in to replace the fat thus taken 
away. The mass is agitated, and rennet enough added to form a 
curd quickly before the oil can separate from the skim milk, in 
order to form an emulsion of oil and a menstruum of solid casein, 
like that which exists in cheese from natural milk. This process 
has succeeded so well that chemical analysis has shown the arti- 
ficial cheese richer than the genuine, and so great an improve- 
ment on skimmed cheese that large quantities are sold in New 
York and shipped to Europe. Under the microscope this artificial 
preparation, on account of the imperfect emulsion formed, shows 
_ cavities of irregular shape in which the artificially introduced fat 
was imprisoned when the curd was formed, instead of the smooth 
mixture of fat globules found in cheese from full cream milk. 
A Rare Sate.—The microscopes, objectives, accessories and 
objects of the late distinguished and critical microscopist, John 
_E. Gavit, are now offered for sale by his son, W. E. Gavit, of 
Stockbridge, Mass., from whom catalogues and particulars can be 
obtained. 
Excuances.—The San Francisco Microscopical Society is now 
enabled, by the kindness of the State Geological Society, to offer ; 
=~ return exchanges of Pacific Coast diatomaceous deposits on re- 
— ceipt of any valuable microscopical material. 
a 
SCIENTIFIC NEWS. 
797. At the end of a course of study at the common 
s 
a Professor Joseph Henry, of the. Bar thioniii Institution, : 
lied May 13th, at Washington, of Bright’s disease of the kidneys. — . 
rofessor Henry was born in Albany, N. Y., on the 17th of De- 
