With proper caution in its use, no serious danger need be apprehended. In the first place, it should never be given in the solid or undissolved form, not even in a state of mechanical division, however minute. It should be exhibited in solution; and, happily, its different menstrua take up so small a portion of it, that it is brought into contact with the stomach in an extremely diluted state, and the combustion of its particles, should this take place, could do little or no injury.* In the second place, it should not be administered when the stomach is quite empty, unless accompanied with copious nutritive or enveloping material, which would secure the mucous surface against its concentrated effect.

* M. Tavignot, however, who has used phosphorus very extensively, affirms that the pilular form is preferable for internal use; being perfectly safe, as he prepares the pills, and much more acceptable to the patient. He first dissolves one decigramme (1.5 grain) of phosphorus in eight grammes (about two drachms) of sweet almond oil, with the aid of a water-bath, and then with eight and a half grammes of butter of cacao, and eighteen grammes of marshmallow, forms a mass, which he divides into one hundred pills. To a child from three to seven years old he gives at first one, and then two pills daily. It will be noticed, however, that even in the pill of M. Tavignot, the phosphorus is really in solution, so that the direction in the text still holds good. M. Tavignot affirms that, in the quantity of four milligrammes (0.060 grain) daily, phosphorus may be given for months without the least danger. He also uses it externally in the form of a liniment, made by dissolving, with the aid of a water-bath, one part of phosphorus in four hundred parts of sweet almond oil, and one hundred parts of naphtha. This is applied by friction, and afterwards by means of flannels impregnated with it. He uses the pills and the liniment conjointly. (Ann. de Therap., l866, p. 100.) - Note to the third edition.

Very different opinions have been advanced as to the suitable dose. A mean between the extremes would give one grain during the day, in divided doses, frequently repeated. The only suitable preparations are solutions in ether, chloroform, olive or almond oil, or some analogous menstruum. Ether and olive oil each dissolves about four grains to the fluidounce. Objections to the former menstruum are the length of maceration necessary, which renders extemporaneous preparation difficult, and the great liability to the loss of the ether, and the consequent precipitation of the phosphorus, when the solution is kept. The solution in oil is preferable, as it is made more speedily, and keeps better. It is prepared, according to the Prussian Pharmacopoeia, in which it is designated as Oleum Phosphoratum, or Phosphorated Oil, by putting twelve grains of phosphorus, minutely divided, into a fluidounce of almond oil, melting the phosphorus by means of a water-bath, and then agitating until solution seems to have been effected. As the oil really dissolves but four grains, the undissolved portion should be separated by decanta-tion or filtration. This oil should be phosphorescent when exposed to the air. The dose of it is from five to ten drops, which may be repeated. in cases of urgency, every half hour; in ordinary cases of debility, every hour or two through the day. It should be given in emulsion with one of the aromatic waters, so made that a tablespoonful may contain a dose of the phosphorus. Dr. R. M. Glover proposes chloroform as a solvent. This dissolves one-fourth of its weight of phosphorus, and has the advantage that the solution is not inflammable. {London Lancet. Jan. 8, 1853, p. 34.) The preparation should be made extemporaneously, in consequence of the great volatility of chloroform. One minim of a saturated solution, mixed with fifteen minims of ether and half a fluidounce of wine, might be given, in acute cases, every two or three hours. Dr. Glover also proposes a solution of phosphorus in cod-liver oil, containing half a grain to the ounce, for use in scrofula. (See U. S. Dispensatory).