The agreeable qualities of fruits may be said to reside in three different factors. First, there is the proportion of sugar, gum, pectin, etc., to free acid; next, the proportion of soluble to insoluble matters; and thirdly, the aroma, which, indeed, is no inconsiderable element therein. This latter quality--the aroma, fragrance, or perfume of fruit--is due to the existence of delicate and exquisite ethers. These subtle ethers Are often accompanied by essential oils, which may render the aroma more penetrating and continued. Those fruits like the peach, greengage, and mulberry, which almost melt in the mouth, contain a very large amount of soluble substances. Some fruits, like the peach and apricot, carry but a small amount of sugar as compared with the free acid they contain. Yet the free acid is not distinctly perceptible, because its taste is covered by a larger proportion of gum, pectin, and other gelatinous substances. There are other fruits again, such as the currant and gooseberry, which are markedly acid, because there is only a small amount of gum and pectin, and a relatively larger amount of free acid. With regard to fruit when eaten in its raw state, the question of ripeness is a most important ones and is always to be considered; so that whatever views may be entertained as to the dietetic value of ripe fruit, there is a consensus of opinion on the fact that when unripe it is most injurious. Care must be taken, therefore, to see that it is perfectly ripe, and no considerations of economy must be allowed to over-ride the fact. At the same time, though ripeness is a necessary qualification of wholesomeness, yet fruit must not be over-ripe, as changes occur which render it undesirable for the system, and thus in avoiding Scylla we may fall into Charybdis. The skin of fruit should never be eaten, nor should the stones, pips, or seeds be swallowed, as there is a danger of their accumulating in a small pouch of the bowel known as the vermiform appendix. Their lodgment in this little pocket is a constant source of peril, and would soon set up an inflammation, which must always be attended with a considerable amount of danger.