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ME BAIRWARY ISS: 
NUMBER 50 NEW SERIES 
Objects Seen Under the Microscope. 
By CHRYSANTHEMUM. 
XXX VII.—Snow aANnp ICE CRYSTALS: 
Ice formations, snow crystals, and hoar frost have been 
subjects of study since the sixteenth century. In the 
year 1555 the learned Olaus Magnus, Archbishop of 
Upsala, published a book containing an illustrated chap- 
ter on snow crystals; but he overlooked the tact that 
crystals are six-sided. The great Kepler published in 
1661 the first special work on these crystals. It was 
devoted mainly to the description of new shapes and 
figures rather than to that of their hexagonal from. 
Other early chemists and physicians described them 
in their own way. One French man, Fabri de Peiresse 
(1623) was of the opinion that they came from seeds, 
like plants and animals. 
Dr. Hellmann has recently published a work in Berlin 
in which he gives a synopsis of all that has been done in 
this direction. From the primitive drawings of Magnus 
to fine illustrations of the present day, the most beauti- 
ful given are by an English meteorologist, James Glasher. 
But these are ideal rather than real, as the true crystals 
do not have the six arms of equal length. Perfect 
crystals can form only when the molecular action is un- 
disturbed, but this condition cannot exist in a snow 
storm. The upper strata of the atmosphere is invariably 
in a state of motion; in the region where snow crystals 
