This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Extractum Nucis Vomicae. U. S. 1850, Br. - Extractum Nucis Vomicae Alcoholicum. U. S. - This contains all the virtues of the seeds. It is more convenient and efficacious than the powder, but like it is liable to the objection of inequality of strength. If the estimate of M. Recluz as to the average product obtained from the seeds is to be relied on, it is about twelve times as strong as the powder. The dose is from half a grain to two grains, and in no case should exceed four or five grains. In persons of an irritable nervous constitution, it would be best to begin with the smallest quantity mentioned. For a child from four to eight years old, the commencing dose may be one-eighth or one-sixth of a grain, which should not be increased beyond one, or at the furthest, two grains. At first, one or two doses may be given daily, which should be increased to three or four doses, before augmenting the size of each. The extract is most conveniently given in the form of pill.
Extractum Ignatiae Alcoholi-cum, U. S. - Under the name of ignatia amara, an extract of the bean of St. Ignatius was a few years since used empirically or popularly to a considerable extent. It is needless to say that so powerful a medicine should never be tampered with, and never employed unless under proper medical supervision. The revisers of the U. S. Pharmacopoeia for the present edition, sensible of this inconvenience, have introduced a formula for the extract under the name at the head of this paragraph. It is prepared by first forming a tincture by percolation and then evaporating the tincture to dryness. The dose is stated at from half a grain to a grain and a half, three times a day; but, considering the relative richness in strychnia of the nux vomica and the bean of St. Ignatius, it would probably be safer to commence with a dose not exceeding at most one-half of that of the extract of the former medicine.
Tinctura Nucis Vomicae. U. S. - This is seldom used internally, on account of its excessive bitterness, while it has no advantage in relation to equability of strength over the powder or extract. If the nux vomica be completely exhausted by the alcohol, the quantity equivalent to five grains of the powder will be twenty minims. This, therefore, may be considered as the proper commencing dose for an adult. As hitherto stated in most books, the dose is too small for effect, unless it may be as a tonic. The tincture is chiefly employed externally, by friction or as an embrocation to paralyzed parts. It may be conveniently diluted with the camphorated tincture of soap, or used as an addition to the liniment of ammonia.