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ELEMENTS OF MATERIA MEDICA.

might be employed. Ammonia cannot be useful, as an antidote, byits chemical properties merely, since hydrocyanate of ammonia is apowerful poison.

(c.) Cold affusion lias been strongly recommended by Herbst ( Archiv .f. Anat. et Phys. 1828 ; quoted by Dr. Christison), and is admitted byOrfila to be a valuable remedy, though he thinks it inferior to chlorine.Herbst says that its efficacy is almost certain when it is employed beforethe convulsive stage of poisoning is over, and that it is often successfuleven in the stage of insensibility and paralysis.

( d .) Artificial respiration ought never to be omitted. Of its efficacy Iam convinced from repeated experiments on animals. I once recovered arabbit by this means only, after the convulsions had ceased, and theanimal was apparently dead. It is an operation easily effected, and willbe found a powerful assistant to chlorine or ammonia, by enabling it toget into the lungs when natural respiration is suspended. To producerespiration, make powerful pressure with both hands on the anteriorsurface of the chest, the diaphragm being at the same time pushed upwardby an assistant. Inspiration is effected by the removal of the pressureand the consequent resiliency of the ribs.

Other remedies (as turpentine) have been recommended, but they will notbear comparison (if, indeed, they possess any efficacy) with those nowmentioned. Blood-letting has been advised, in vigorous subjects, whenrespiration has been established, and the skin is livid (Devergie, Med.Ley. t. ii. p. 825).

Order 8.—Phosphorus and Phosphoric Acid .

Phos'phorus — Phos'phorus.

History. —This substance was discovered in 1669, by Brandt, analchymist at Hamburgh ; and received its name from being luminous inthe dark (from <pwg, light; and <j>lpto,I carry).

Natural History.—P hosphorus is found in both kingdoms ofnature.

(a.) In the inorganized kingdom. —Phosphorus is comparatively rare inthe mineral kingdom. Various phosphates are found native, but in smallquantities : those of lime, lead, iron, copper, manganese, uranium, andyttria, may be mentioned as examples. Phosphate of lime is an impor-tant constituent of the organic exuviae entombed in the fossiliferousrocks.

(6.) In the organized kingdom. —Phosphoric acid, free, or combined withlime, potash, or iron, is found in various vegetables (Decandolle, Phys.Veget. pp. 383, 387, and 390). Phosphorus is a constituent of animals:in some cases it is in combination with oxygen, and a base, as in thebones, urine, &c.: in other instances, as in the brain, it is uncertain inwhat form it exists.

Preparation. —Phosphorus is procured from bone-ash (sub- or f phos-phate of lime), by digesting it in sulphuric acid; by which sulphate andsuperphosphate of lime are procured : the first, for the most part, preci-pitates, while the latter remains in solution. The solution is to beevaporated nearly to dryness, then mixed with charcoal, dried,and distilled in an earthen retort. The charcoal abstracts the oxygen