chemical properties is shown by the acids and alkalis. There are certain compounds in chemistry, which are distinguished by a sour taste, and are therefore termed acids. They have also the property of altering certain coloring matters. In opposition to these acids stand bases, and the soluble bases, or alkalis, which are caustic like the acids, and turn reddened litmus blue again. In the combination of acids and bases to form salts, both lose their characteristic peculiarities, and even their peculiar taste, and then have a different one, either a saline taste, as in chloride of sodium, or a bitter taste, as in sulphate
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of magnesia, or even a sweet one, as in acetate of lead.
ZOOM-IN ÂŤ Microscopic investigation The anatomical and microscopic investigations of the organ of taste afford a much safer standpoint. The entire surface of the tongue is covered with little elevations called gustative papillae, which are invisible to the naked eye. Some of them terminated in a bundle of fibers, and others are broad and bushy on their surface. At the root of the tongue a semicircle is formed by a larger papillae, each of which is surrounded by a circular mound. Small depression have been observed surrounding these circumvallated papillae. The papillae stand in the depressions formed by the mounds, and are filled internally with oblong cells, which are connected by prolongations with nerve-fibers. Similar organs have been observed upon the other papillae of the mucous membrane of the tongue, and it is probable that in them we must look for the true instruments of taste.
SENSING SURVIVAL
D EVOU R
S A MP LE
P ERCEIVE
S AVOU R
RELIS H
BASK
D EP LETE
EXP END
EATEN
AT E
ING ES T
E AT
COMP REHEND
IND ENTIFY
TA K E IN
HAVE
TRY
A better agreement between taste and