Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/280

258] NAR A, B, the pitce of timber, in which the nail or spike C, intended to be drawn, is inserted. D, E, the slwpe of the tool, con- sisting of a lever, D, that moves on a solid basis, in the form of a seg- ment of a circle, as at E. F, a square staple, taming on a centre at G : and, if the spike to be drawn, be held between the lever and the staple, any pressure at D, will at with an effect pro- porLionats to the distance a F, andDa; and the workman will thus be enabled to exert a very great force against the spike C. Mr. Hich's nail-drawer is both simple and ingenious -, it is emi- nently serviceable in breaking up ships, and on other occasions, ■where large nails and spikes have been driven deeply into wood, from ■which they are to be extracted. Nail-wort. See Whitlow- grass the Common. Naphtha. SeeBiTUMENS. NARCOTICS, a term compre- hending opiates, anodynes, or pa- regorics, and all other drugs which induce sleep, or occasion stupe- fa 6lion. The narcotics chiefly employed in medicine are, opium, henbane, hemlock, &:c. respecting which the reader will, in the order of the alphabet^ find a concise account of the cases in which they may b"f? used with advantage. Whatever tends to induce stu-- por, ought to be carefully avoided> or at least very cauti:Jf)usly adminis- tered, in disorders of the stomach and intestines ; for no other class of drugs is produfitive of such per- nicious consequences to the ner- vous system. If taken in very small doses, narcotics at first excite and increa'ie the action of the nerves^ while they produce gentle undula- tions of the circulating blood ; but, in a larger proportion, they stimu- late, and at length reduce or debi-- litate, all the nervous and muscu- lar functions. Thus, their conse- quent effect: is similar to that of tvliie, which, if used in modera- tion, promotes a temporary aiStivity, by invigorating the nervous power, or rather, by causing an additional niotion (which in physic is called tongesfionj of the fluids towards the head 5 but, when drunk too freely, it weakens and stupifies all the sensitive organs, by the unu- sual pressure it causes on the brain. Hence it will be readily inferred, that such heroic remedies can be presci-ibed with safety, by those only who are acquainted with the animal economy. NAUSEA, or Sickness, de- notes a propensity and exertion to vomit.