FLAVOUR SENSATION.

King Country Chronicle, Volume VI, Issue 476, 22 June 1912, Page 7

FLAVOUR SENSATION.

WHAT YOUR TONGUE CAN TELI YOU. It is not generally known, says Mr. Lawrence Hodges in a paper that induces thought, that we can taste only four different kinds of matter ; that is, perceive by means of the tongue no more than four taste qualities of matter. They are sweet. sour, bitter, and salt. If one holds his nose and places on his tongue iD succession pieces of apple, onion raw potato, and beet, he cannot tell the difference between them. Bj these experiments it has been determined that the sense of smell has g great deal to do with the flavours perceived or taken cognizance of b3 the brain. As the tongue can distinguish only these four sensations it is at once seen that other varia tions in taste are due to the sense of smell. In some cases, as with the orange, all the flavour is in the smell ; so when we eat an orang< while we have a cold no taste is ap parent.

These four sensations also hav< not their respective seats distributee uniformly over the tongue. Sugai and other sweets are perceived at th< tip of the tongue, as are also salty things. If a little sugar is placed cr :hc back of the tongue, no sweetness is apparent. The locus of sour anc" bitter- perception is back further ii the mouth, and placed on the side; of the tongue. Both these facts are easily proved by experiment. Another peculiarity of taste per ;cption is that dry things cannot be tasted ; only those that are in solution. If a dry biscuit is placed 01 the tongue, no taste is apparent until the saliva has dissolved part 6 it. If the tongue is wiped dry witl a handkerchief, and a little sugar is placed on it, no taste is perceive*' tor some time.

The mechanical arrangements pro vided by the body for the perceptioi of taste are also interesting. In the mouth, situated in the places men tioned as seats of taste perception and also in other places, though not so thick, are what are kno.vn a; "taste buds." They get this name from their almost exact similarity to a bud when cut in cross section These taste buds have in them tht excessively fine branches o' the nerves of taste that carry the impulse to the brain.

The only reason a great man' things a r c tasteless to us is becavs; they are not' soluble in water 01 saliva. Take sand, for instance, 01 lead or gold. None of these give any taste on that account. The tongue, of course, has many uses besides being organ of taste One of the chief of these is the ability of its end to perceive very slight touch sensations. The tip o the tongue is proved by numerous experiments to be the most delicate touch perceiver in the human body Of course, the floodgates of tht saliva duets are controlled by nerve:from the brain. One or two peculiar experiments can be tried to show re suits of thought on their onerati mi. If one thinks about sucking a 1-uno: or about eating a luscious pear, himouth immediately receives an cxtrr flow of saliva—the mouth watrrs for them. If a person is frightened, the flow of saliva is stopped, an:! i;n mediately afterwards one perceives that his mouth is extraordinarily dry and cannot account for it.