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Materia Medica.

Part II.

It

and by treating it with a sufficient quantity of nitric acid, form-ing a portion of camphoric acid ; and by treating it with sul-phuric acid, forming artificial tannin.

But the production of camphor is not confined to the lau-rus camphora, although it furnishes almost all the camphor ofcommerce; it is found in very great purity in interstices a-mong the woody fibres of an unknown tree in Borneo ; it isalso contained in the roots of the laurus cinnamomum andcassia, alpinia galanga, amomum zedoaria, &c. •, in the seedsof the amomum cardamomum, piper cubeba, &c.; and in ma-ny indigenous plants, as in the thymus serpyllum and vulga-ris, juniperus communis, rosmarinus officinalis, salvia officina-lis, mentha piperita, &c. and may be separated from the es-sential oils of rosemary, lavender, marjoram, and sage. Anartificial camphor, differing from common camphor, in notbeing soluble in weak nitric acid, nor being precipitated bywater from its solution in strong nitric acid, may also be pre-pared, by directing a stream of muriatic acid gas into oil ofturpentine. Camphor is now universally considered to be apeculiar principle of vegetables, and not a resin, as incorrect-ly stated by the Dublin College.

Medical me. —Camphor is a very active substance, whentaken into the stomach. It increases the heat of the bodyconsiderably, and gives a tendency to diaphoresis, but with-out quickening the pulse. At first it raises the spirits, butproduces a subsequent depression, and facilitates voluntarymotion. In excessive doses it causes syncope, anxiety, retch-ings, convulsions and delirium. These violent effects of cam-phor are most effectually counteracted by opium.

In a morbid state of the body, camphor allays inordinateactions. When the pulse is hard and contracted, it rendersit fuller and softer. It removes spasms, and flitting pains a-rising from spasms ; and in delirium, when opium fails of pro-curing sleep, camphor will often succeed. It is also said tocorrect the bad effects of opium, mezereon, cantharides, andthe drastic purgatives and diuretics.

The most general indication for the use of camphor is thelanguor or oppression of the vis vitce. It may therefore begiven with advantage,

1. In all febrile diseases of the typhoid type, especially when

attended with delirium.

2. In inflammations with typhoid fever, as in some cases of

peripneumonia and rheumatism.

3. In eruptive diseases, to favour the eruption, or to bring

it back to the skin, if from any cause it has sudden-ly receded, as in small-pox, measles, &c.