If any of its crystals can be obtained, we shall be immediately able to identify them. They dissolve very readily in water, and since the oxalic has a greater affinity for lime, than any other acid, and forms an insoluble salt with it, we have thus a ready test of its presence, for it will decompose all the calcareous salts, not even excepting the sulphate.
Boiling Water.
Many cases are recorded of the death of children from the ingestion of boiling water; an accident which will be always liable to occur, as long as the peasant allows his family to quench their thirst by drinking the cold water through the spout of the tea kettle. It has been very generally supposed that fatal effects have, on these occasions, supervened the high state of inflammation produced in the æsophagus and stomach by the boiling liquid. Dr. Marshall Hall has, however, lately published a very interesting paper on this subject, in the twelfth volume of the Medico-Chirurgical Transactions; from which it would appear, that the patient, under these circumstances, actually dies of suffocation as in croup; and that the boiling water is arrested in its progress to the stomach by the convulsive action of the muscles of the pharynx. In passing, however, to the posterior part of the mouth, it scalds the epiglottis, and glottis, which afterwards become more and more swollen, until at length the rima glottidis, or orifice into the larynx, becomes completely obstructed. Here then we have a new instance in which the operation of laryngotomy, or of tracheotomy, may be performed with the effect of preventing impending suffocation, and perhaps of saving life. Dr. Marshall Hall relates four cases in illustration of this interesting fact; of which one recovered from imminent suffocation immediately after screaming[[327]]; two died from suffocation, one 10, the other 17 hours, after the accident; the fourth was completely relieved by the operation of tracheotomy, and survived 34 hours, but died, exhausted by the irritation produced by the primary affection.
Melted Lead.
An instance stands recorded in the history of the destruction of the Eddystone-light house, by fire, where a quantity of melted lead fell into the mouth, and was swallowed by a person who was attentively watching the conflagration. It is very singular, that this man lived many days after the accident; a fact which at least shews what extensive injury the stomach will occasionally sustain, without the immediate destruction of life. The lead taken out of the stomach after death, in this case, weighed exactly seven ounces, five drachms, and eighteen grains.[[328]]
The Caustic Alkalies.
These bodies are distinguished by a highly corrosive and peculiar taste; they change the blue[[329]] juices of vegetables to a green, and the yellow to a brown; they are soluble in water, and have the power of imparting the same property to oils, by combining with them, and thus forming saponaceous compounds. With the different acids they constitute peculiar salts. When applied to the flesh of animals they act as powerful caustics, destroying its texture, and ultimately dissolving it; they are accordingly arranged with great propriety under the head of corrosive poisons.
There are three[[330]] alkalies—potass, soda, and ammonia. To the two former the epithet fixed has been applied, since they require a very high temperature for their sublimation; while to the third, that of volatile has been assigned, because, when uncombined, it exists in a state of gas. Potass, as it was considered the product of vegetation, has received the name of the vegetable alkali, while soda, as the base of rock salt, has been distinguished by that of mineral alkali. The distinctions, however, originally established by Avicenna, must now be abandoned, for they have not the slightest foundation in truth; potass, so far from being the exclusive product of vegetation, exists as a constituent part of the Granite, which forms the foundation of our globe; it has also been discovered in the Pumice stone; in some minerals of the Zeolite family; in the Leucite; in the aluminous ores of La Tolfa, &c. and, although potass is undoubtedly procured by lixiviation from the ashes of burnt wood, and other vegetable substances, yet there is ample grounds for supposing that the living plant receives it from the soil in which it vegetates.
Potass, or Potash—
Liquor Potassæ—Potassa Fusa, or Kali Causticum—Lapis Infernalis—Causticum commune acerrimum. Potassa cum Calce—Potassæ Sub-carbonas, or Salt of Tartar—Potash—Pearl ash.