Experiments with buttermilk feeding have been made of recent years, especially in children whose digestive organs were not able to digest the amount of fat contained in ordinary milk or in mixtures of milk and water and cream. The results obtained have proved buttermilk to be an excellent food in certain disturbances of nutrition.
During the second half of the first year the digestive juices are secreted in the infant as in the adult, and feeding on cows' milk ceases to furnish the necessary nutritive substances, especially salts, iron, and phosphorus com binations. At this period it is advisable to commence the use of various flours in addition to the milk. A number of infants' foods containing the necessary salts are on the market, but the attending physician had best be consulted with regard to the choice of any of these. Ordinary ground Zwieback, flour, or rice may advantageously be used for the preparation of a pap. When the infant is old enough to take undiluted milk, it may also be given broths which contain the salts of meat ; and the feeding then becomes a matter of careful observation and experiments with various foods. The first experiments with soup had best be made with a thin broth made of veal bones, with the addition of the yolk of an egg, a little salt, and one or two teaspoonfuls of meal. At this time most infants willingly take a crust of bread, a piece of zwieback, or a dry cake.
The growth of the infant must be tested at regular intervals by weighing it on a suitable scale (see Fig. 307). Almost any scale will answer the purpose, except the dial-scales com monly used in kitchens, as these do not always give reliable results. The following table of weights may be useful in showing the progressive weight of a healthy baby which weighed 7?-, pounds at birth.
Under certain conditions, to be considered by the physician, it may be necessary to engage a wet-nurse. This is especially indicated when a baby fails to thrive on artificial foods, and the mother is unable to nurse the child herself. In selecting a wet-nurse, it is of the greatest importance to the welfare of the infant that the applicant be carefully examined with regard to her health, and also that the condition of her own baby be considered. A wet-nurse should not be less than 20, nor more than 35 years of age. Her baby must be at least to to 13 weeks old, and well nourished. Upon repeated inspection it must show no sores whatever. The wet-nurse herself should be subjected to a careful medical examination, unless one would run the risk of exposing the baby she is to nurse to the danger of infection by syphilis, tuberculosis, or other contagious diseases.
NUT-GALL.—See GALLA.
NUTMEG (MYRISTICA).—The arils, or shelled seed, of the iltyristica fragrans, or nutmeg-tree, indigenous to the Molucca Islands, but largely cultivated both in the East- and \Vest-Indies. The seed is oval in form, greyish and furrowed externally, and yellowish with darker veins internally. Its odour is pleasingly fragrant, and its taste delightfully aromatic. The
medicinal properties of nutmeg depend upon the various oils which it contains ; but it is not now used to any great extent, except as a means to disguise the taste of nauseating remedies. It is used also for its stimulating effects upon the appetite.
NUX VOMICA.—The seeds of the Strychnos Nux-vomica, a middle sized tree growing in the East Indies. The seeds arc little, flat discs, about an inch in diameter, and having a very bitter taste. Nux vomica depends for its action on the presence of two poisonous alkaloids, strychnine and brucine. Of these, strychnine is the more powerful, and its action predomi nates. When taken in small doses, nux vomica acts like any other bitter tonic, increasing the flow of the digestive juices and improving the appetite. It also stimulates the special senses (as sight and hearing), rendering them more acute. Respiration and circulation are both stimulated by strychnine, and all the reflexes are rendered more active. Larger doses cause some muscular twitching, and an exaggerated sensitiveness to the slightest irritation. This is a manifestation of the predominant action of strychnine, an increase in the excitability of the motor portion of the spinal cord.
In poisonous doses the irritability becomes so extreme that any slight stimulation, such as the banging of a door or a draught of air, will cause violent convulsions. The body is thrown into an intense spasm, the back being arched so that only the heels and the head touch the ground ; breathing is suspended, and the face is drawn into a horrible, spasmodic grin, the rises sardonicus. There is some trembling, but no active movement after the muscles are set. The face becomes purple from the want of air. Conscious ness is retained until death sets in, which usually results from asphyxia and exhaustion. In case of poisoning, the stomach should be emptied as soon as possible, and tannic acid given. For the rest, the treatment consists in avoiding all irritation, and combating the convulsions with such depres sants as bromides and chloral. Nux vomica is valuable as a bitter tonic, the tincture being given in doses of 5 to 15 minims. Strychnine is used as a stimulant to the heart and respiratory apparatus, especially in heart diseases, depressing fevers, surgical shock, poisoning by depressant drugs, etc., etc. The dose is about one-fiftieth of a grain.
NYCTALOPIA.—Term indicating a condition in which a person sees better at night than in the day time. It is sometimes due to central opacities of the cornea or lens, in which condition the power of vision would naturally become increased when the pupil is dilated, as occurs when darkness sets in. Day-blindness may occur also in some diseases of the retina, in which the central portion of the visual field is excluded while the external parts are visible. A similar condition is caused by tobacco-poisoning ; and in recent cases of this affection abstinence from smoking generally suffices to effect a cure.