Page:The New International Encyclopædia 1st ed. v. 14.djvu/818

* NUTBITION. 696 NUTTALL. on in the digestive canal and by the secretions of the y:lands (<i.v.) which open into it. The phe- nomena attending the ehihoration of food and its preparation for assimihition liy the tissues are described under DloESTlox, Orua.ns of. In order that nutrition may be carried on in a liealtliy manner, certain conditions must be present. The blood must be normal in composi- tion and amount, and circulate with suitable rapidity; there must exist a certain nervous stimulation and control; ami the part to be nourished must be able to ajjpropriale the ma- terials brought to it by the blood. The depend- ence of nutrition upon the first of these condi- tions is shown in ameraia, in which disease the contents and carrying capacity of the blood are lowered, and nutrition corres|iondingly depressed. The inlluence of the nervous system is demon- strated by the atrophy or even death of a part which follows the destruction or cutting oil' of its nerve supply. This often happens in certain diseases of the spinal cord. It is not only necessary that the body should be .supplied with food in order that its natural functions may be performeil, but it is eiiually nece.~-sary that the food supplied should consist of the proper materials. Each animal by instinct seeks those substances which best meet the needs of its own metabolism, and it is a matter of everj'-day experience that man endeavors to sup- ply himself with food suitable to the conditions under which he lives, and alters his diet with respect to season, latitude, age, activity, and occupation. Food is intended to supply the place of that which is given out by the liody. But in the choice of diet this is not enough: the food should be sullicient to meet such needs without waste, and without increasing unduly the out- put of excreta, while the organism should be maintained in health. Careful analysis of the excreta shows that they are made up, l)esides water, chiefly of the chemical elements, carbon, hydrogen, oxygen, and nitrogen, but that they also contain, although in smaller amounts, sul- phur, chlorine, potassium, and certain other ele- ments. To balance this waste it is evident that food must be supplied containing all these ele- ments in something like the proportion in which they are excreted: that is, a 'niixed diet' is neces- sary. Experiments upon the lower animals have shown that a diet composed exclusivelv of one class of food, such as fat, or sugar, results in the death of the animal after a longer or shorter period of time. Sec Diet. The subject of nutrition is exhaustless. It comprehends all vital iiliiimnicna. for none of the functions of life are iierfornied without involving replacement by living matter, and therefore nu- trition. The subject of hygiene in all its aspects is connected with it, whether in eating, drinking, exercise, sleeping, or breathing. A change in each of these processes involves a corresponding change in the elaboration and appropriation of new material, and the disassimilation or elimi- nation of old, or its reconversion. Tonsutt the chapters on "Xutrition and Diet," in Kirke, flnnillinolc <<f Phiiniolofii/ (Philadelphia, 1002) : and Foster. TrxtliiiiiU of /'/i.i/su'o/oi/t/ (Xew York. mno). See Respiration; Secretion. NUTBITION (in Plants). Tn its widest sense the nutrition of plants includes all pro. cesses by which fond is obtained and used, The food of plants consists of organic material. Even the green plants require organic food, which they manufacture out of the simpler substances, car- bon dioxid and water, that they absorb. The mode in which plants obtain both foods and the materials out of which foods cau be made, is de- scribed under the head of Absorptiox. (For the nature of the materials which plants require, see Food of Plants.) Reserve foods are stored in the special tissues or organs. Such materials must be moved first from regions of absorjition or manufacture to the points of storage, ami after digestion at some later time thence to the re- gions of growth. Having been brought to the regions of growth, some of the food ii used for the supply of energy to the protoplasm, either directly or after incorporation into the substance of the protoplasm itself. The energy is released through the process of oxidation and the by- products are carried away. All processes of nu- trition connected with the release of energj- for growth and movement constitute the function called res]iiration (q.v.). Other portions of the food are utilized for the making of new parts. See Growth: I'hotosyntuesis; Assimilation; Storage; Digestion. NTTTT, nut, Aured Tribner (18.50—). An English folk-lorist, born in London, and edu- cated at the University College School ami the College de Vitry, France. He studied the pub- lishing business in Leipzig. Berlin, and Paris from 1874 until 1877, and then succeeded to that of his father in London. He wa.s one of the original members of the Folk-Lore Society, be- came its president in 1897, and was a founder of the Irish Texts Society in 1898. His publica- tions are: The Lri/i'itd of the IJohi (Irnil. irith Especial Reference to the Hi/polhesis of the Cdtic Oriiiiii ( 1888) and The Voyage of Bran (2 vols., 1895-97). NtTT'TAIiL, Thomas (IVSOlSon). An Ameiican ornitliologist and botanist, born at Long Prcslon, Settle. England. He came to the United States in 1808, and went West. Though an ardent ornithologist, and constantly in the wilderness, he rarely carried a gun. In 1822 he was made professor of natural history at Harvard I'ni- versity, but gave only irregular instruction, de- voting himself mainly to the culture of the botanic garden, founded in 180.5 by his predeces- sor. Dr. V. D. Peck. He remaiiu'd in Cam- bridge ten years, and wrote and published The Genera of Xorlh Amerietin I'lantyt (1818) and .1 Manual of the Ornitholoii;/ of the I'nileil Statm and Canada (18.32-34), in two volumes, which is a classic in American science. A second en- larged edition was publishcil by Xuttall in 1840; and a third edition, with notations by M. Chamberlain, was published in I?oston in 1890. Tn 18.34 Xuttall suddenly resigned his profes- sorship and started on an ex))editii>n to the Pa- cific Coast, led by Captain yetli, and accom- panied by another naturalist. .1, K. Townsend, who published a Xarralive of the journey ( 18,30). From California he went on to the Sandwich Isl- ands, whence he returned around Cape Horn, in the vessel which had among its crew Richard H. Dana, author of Tim Years Hefore the Mast. Xuttall then settled in Philadelphia and prose- cuted scientific study and writings for a few years. After publishing a second edition of his Omitholofii/ (1840), and a f^iippleinent to >ri-