SPONGIA, MEDICAL USES OF. The use of sponge by surgeons, in its natural state, to absorb fluids, needs no notice, but it is also employed by them under the name of sponge tent, when prepared in a particular manner. This consists in dipping the sponge in melted wax, and compressing it between iron plates till it hardens on cooling; it is then cut into cylindrical or other forms. The pieces are intro duced into sinuses and other narrow canals, with the intention of dilating them by the expansion of the sponge, when the wax melts by the heat of the part. Sponge tents are however little used by modern surgeons.
According to the analysis of Hornemann, sponge consists of a substance similar .to ,osmazome, animal mucus, fat nil, a substance soluble in water, a substance only soluble in potash, and traces of chloride of sodium, iodine, sulphur, phosphate of lime ( f), silica, alumina, and magnesia.
When sponge has been cut into pieces, beaten in order to free it from little stones and shells, and burnt in a closed iron vessel, till it is black and friable, it is then called burnt sponge (shingle sate). As
the virtues of this greatly depend on the proportion of iodine con tained in the sponge, much of which is volatilised by the high temperature required in calcination, it has been proposed only to expose it to such a heat as will thoroughly dry, colour it brown, and render it friable, when it may bo powdered, and preserved in well closed bottles. For use it is generally formed into an electuary or into lozenges. A test of its goodness consists in heating it in a glass flask with sulphuric acid, and if copious violet-coloured fumes be evolved, this proves that it contains much iodine. Burnt sponge, has been shnost completely superseded in the treatment of bronchocolo and scrofula by iodine and its preparations ; but as it obviously consists of a natural combination of many of the principles which have been deemed useful in scrofula, it ought not to be hastily discarded. It is with great propriety retained in the Dublin Pharmacopoeia.