88 SNOW CRYSTALS. 



The Cuticle of the Tongue.— On an empty stomach, the surface 

 of the tongue is scraped with a spatula or tongue-scraper. We 

 take a small particle of the product and put it in the aniline water 

 previously deposited on the slide. Afterwards it is carefully divided 

 and coloured like the patina dentaria. However, owing to the 

 superposed epithelia, these preparations can never be properly 

 thinned, and therefore are only in a few points rendered clear 

 enough for investigation under high powers. 



Snow Cri?6tal9* 



By J. H. 



IT is almost impossible to imagine the extreme beauty and 

 variety presented by snow crystals. During a sudden fall of 

 temperature lasting only a few days in the last winter, very 

 many intensely beautiful forms of crystals were preserved by the 

 aid of photomicrography. Very many were made up of prisms of 

 six facets. Many presented the appearance of being double ; that 

 is, two crystals alike in form were united to an axis at right angles 

 to the plane of each. These were generally fine examples of the 

 less minute crystalline bodies ; the rays proceeding from the under 

 crystals in most cases filling the intermediate space between those 

 of the upper, and as crystals of a more complex order, and in 

 most cases exhibiting a richness of effect hardly to be exaggerated. 

 It was to me an extremely agreeable study of the various compli- 

 cated forms presented to the eye, whether observed by a low 

 power, or seen by the aid of the microscope, in all their beauti- 

 ful details. A country friend engaged in a similar pursuit 

 made a series of sketches^ drawn about their natural size, with a 

 crowquill ; while another presented me with sketches made about 

 the same time as my own, some of which presented wonderful 

 details, surpassing any of those I had observed. 



A collection of snow crystals, accurately recorded, might, it 

 appears to me, be made to present an interesting feature in 

 meteorologcal investigation. At the same time, it is highly pro- 

 bable that the conditions of their formation are more complex than 

 might be imagined, familiar as we are with the conditions relating 

 to the crystallisation of water on the earth's surface. 



