Dilute Phosphoric Acid. Phosphoric Acid dissolved in Water. It contains between 9 and 10 per cent. of tribasic Phosphoric Acid, 3 HO, PO5, in solution in Water. Sp. Gr. 1.08.

Med. Prop. and Action. Tonic, refrigerant, and aphrodisiac. In large doses, it acts as a powerful stimulant of the nervous and vascular systems; it is absorbed into the system, and has been detected in the blood; it also communicates a peculiar odour to the breath. In very large doses it is an irritant poison; convulsions and insensibility preceding death. (See also Phosphorus.) Dr. Pavy's || experiments with this acid, showing that when injected into the duodenum it is capable of inducing a diabetic state of the urine, are both important and interesting.

Dose, ex. - xl, diluted in sugar and water.

2067. Therapeutic Uses

In Typhus and Typhoid Fever, it has been given with advantage. In the epidemic fever which appeared at Stockholm in 1842, Prof. Huss¶ employed Phosphoric Acid in all the cases which came under his notice. F3iij. of the acid were diluted with fxij. of Decoct. MalvAe; and of this, one or two dessert-spoonfuls were given every two hours. He commenced its use when the pulse began to lose its fulness, and the first sound of the heart became short like the second.

* Journ. of Psych. Med.. July 1849. Epileptic and Convulsive Affections. &c , Lond. 861.

Mod. Times and Gaz., April 5,

§ Med. Times and Gaz., Julv 6, 1801.

|| Guy's Hospital Reports, 1861, vol. vii. ¶ Dub. Journ., Sept. 1845.

2068. In Scrofula, Mr

Balman* states that he has seen Phosphoric Acid exercise a very beneficial effect in a large number of cases; and that he does not hesitate to assert that, as a therapeutic agent, it will be found in no degree inferior to Iodine, Cod Liver Oil, or Barium. "Its effects," he observes, "are sometimes very marked in those obstinate forms of strumous con-junctivitis which sometimes resist for a long period every kind of treatment, and at other times will quickly disappear under the influence of some simple local application; but which perhaps will as speedily return under the slightest exciting cause." In Intermittent Forms of Ophthalmia, arising in a Scrofulous Constitution, he found this medicine of especial service, not only in completely removing the disease, but also in preventing its recurrence. He prescribes it in doses of ev. of the dilute acid, gradually increased to exx. or more, in infusion of Calumba. Thus given, it may be continued for any length of time without producing any unpleasant effects. He is undecided whether its beneficial effects are confined to its tonic influence, or whether they exercise some more specific influence upon the blood and system generally.

2069. In Dropsy, it has been employed as a stimulant tonic, in purely chronic and asthenic cases. It is of very doubtful value as an internal remedy; but it has been attended in some cases with apparent benefit, diluted with oil and used as an embrocation on the abdomen.

2070. In Calculous Disease, Phosphoric Acid has occasionally been employed with a view of correcting alkalescence of the urine. In the phosphatic diathesis, it was administered by Ber-zelius, in increasing doses, but without effect, until it produced purging; after which the urine became rapidly acid, and deposited a lithic acid sediment. In a case related by Mr. Balman, after the Nitric, Hydrochloric, and Acetic acids had been administered successively without effect, he found the Phosphoric Acid of great service, acting as a tonic to the digestive powers, and diminishing the quantity of ropy mucus in the urine.

2071. In Diabetes, Phosphoric Acid, largely diluted, assuages the inordinate thirst so common in this disease, more effectually than any other acidulated drink. (Paris. §)

2072. In Cardialgia, Dr

Todd states that he has employed Phosphoric Acid with excellent effect.

* Med. Gaz., Aug. 22, 1851.

Trait, de Chimie, vol vii. p. 414.

Med. Gaz., Dec. 1, 1848. § Pharmacologia.

2073. In Caries, Phosphoric Acid, diluted with eight or ten parts of water, was locally applied by Lentin,* under the idea that the disease arose from a deficiency of Phosphoric Acid in the bone. In some instances it appears to have been beneficial. It is also supposed to exert an influence on the growth of Osseous Tumours.