The starch which is used for domestic purposes is an artificial preparation, and does not properly represent the starch of nutrition. A better idea of it is afforded by _the meal of a flowery potatoe_. The starch used by laundresses is frequently prepared from diseased potatoes. This does not impair the quality of the starch, for the purposes of the laundress, and the reason why potatoes that are diseased are thus applied is, that it is one method of saving some part of their value. The finest kinds of starch are prepared from rice. It is prepared by breaking the pulp, and disengaging the starch from the cells; and it is then put through other processes to remove the fragments of the broken cells. But in the flowery meal of the potatoe, the starch cell may be seen entire. CHAPTER LXII. 1204. _What are vegetable oils and fats?_ Vegetable oils and fats constitute, next to starch and sugar, the most important secretion of the vegetable creation. There are very few plants from which some amount of oil cannot be obtained; and those which are famed for yielding it owe their celebrity rather to the abundance that they yield, and the peculiar qualities of their oil, than to the secretion of oil being rare--for probably there is no plant without it. Oil is most commonly found in seeds, as _rape-seed_, _linseed_, &c., but it is found also in leaves, as in the rose, sweet-briar, peppermint, &c., where its presence may be recognised by the distinguishing perfume; and it is also found in the wood of a few trees, such as the sassafras and the sandal-wood; the bark frequently yields an oily secretion. [Verse: "Ointment and perfume rejoice the heart; so doth the sweetness of a man's friend by hearty counsel."--PROVERBS XXVII.] The London and North Western Railway Company alone use about 50,000 gallons of oil yearly. 1205. _Why are fat and oil found most abundantly in the bodies of animals in cold climates_? Because they contribute to keep the _bodies of animals warm_, not only by their non-conducting property _keeping in_ the heat of the animals, but by supplying _carbon_ abundantly to combine with _oxygen_ during respiration, and thereby developing _animal heat_. 1206. _Why are oil and fat-forming trees found most abundantly in hot climates?_ Because, in hot countries, the formation of large quantities of fat in animal bodies would oppress living creatures with heat; fats and oils are, therefore, produced in those countries chiefly by vegetables, and are used externally by the Asiatics and Africans as an _external_ unction for _cooling the skin_, and as _perfumes_ which give inspiriting properties to the air, rendered oppressive by excess of heat. 1207. _Why are succulent fruits most abundant in tropical climates?_