1880. | Microscopy. ; 463 
- gypsum, which is but sparingly soluble in hot water, but which 
may be dissolved with muriatic acid; when this is present the 
solution gives a precipitate with chloride of barium. It is also 
readily recognized by the microscope when polarized light is used. 
Tartrate of calcium—this is almost insoluble in boiling water—is 
soluble easily in hydrochloric acid, and gives a precipitate with 
ammonia and oxalate of ammonia. The quantity of this must 
exceed seven or eight per cent. before it can be reckoned as an 
adulterant. Milk is another subject about which the controversy 
seems to be needless. The list of adulterations found in the books 
is a long one, but when thoroughly investigated, it seems to nar- 
row down to about two or three. Water is added in considerable 
quantities, a little burnt sugar is then added to bring up the color. 
ne or two other substances are sometimes classed as adulterants, 
skimmed for whole milk. This fraud can easily be detected by 
the microscope. Milk that has been skimmed is comparatively 
free from large fat globules. Sugar as sold here is perhaps as 
pure as sold at any place in the world. Candy, however, is like 
all manufactured articles, to be looked upon with suspicion. The 
flavoring matters are rarely what they purport to be, and in some 
cases are violent poisons. At the present time the article is made 
largely of glucose, which is manufactured from corn starch. I 
see no objection to the use of this, provided it is well made and 
purified. In the examination of meat the inspector has to rely 
largely on his senses and his familiarity with the genuine article. 
The microscope comes in play here to detect certain diseased 
conditions, and to show encysted parasites, such as Tyichina 
spiralis, 
Avoid hasty conclusions about adulteration. Persons often 
take a look through their microscopes at articles of food and rush 
into print their discoveries, when a few hours’ patient investiga- 
tion of genuine articles about which there could be no doubt, will 
A NEW “GrROwING SLIDE” FOR MINUTE ORGANISMS. — Mr. 
Julien Deby, vice-president of the Belgian Microscopical Society, 
