As the effects of muriatic acid do not differ from those which have been described, as the consequences of poisoning by the other mineral acids, it will be unnecessary to enumerate them. _Orfila_, however, remarks, that the patients who have swallowed a certain quantity of it, emit, in the first moments of the accident, a thick smoke of a white colour, and very pungent smell. _Chemical processes for the detection of Muriatic Acid._ This acid, in its free state, immediately announces its nature by the fumes which it emits. When the acid, however, exists in a more questionable shape, as in the matter vomited by the patient, or in that found in the digestive canal after death, it will be necessary to saturate the liquid part with pure potass, and to boil it for some time, when we shall obtain a fluid, from which the nitrate of silver will throw down a dense precipitate. By evaporation, we shall obtain a crystallized muriate, which may be identified by the following tests: 1, When concentrated sulphuric acid is poured upon it, a brisk effervescence is immediately occasioned, and the muriatic acid is disengaged in the form of white vapours, which are thick, and of an excessively pungent smell. 2, If instead of employing concentrated sulphuric acid, this acid be used in a state of dilution, and the muriate be mixed with some substance which easily yields its oxygen, the muriatic acid will be decomposed, its hydrogen, combining with the oxygen so as to form water, while the chlorine will be disengaged, and by its pungent and peculiar odour at once announce the nature of the acid under examination. OXALIC ACID. _Acid of Sugar._[325] This salt occurs in small crystals, whose form is that of a four sided prism. It is extremely acid to the taste, so that by applying the tongue to one of its crystals, its nature may be immediately discovered. It dissolves in twice its weight of cold, and in an equal weight of hot water; it is also soluble in boiling alcohol which takes up about half its weight; the solutions act powerfully on the vegetable colours, and at once denote their acid properties. On account of the strong resemblance which the crystals of this acid bear to those of sulphate of magnesia, or _Epsom_ salts, many fatal accidents have occurred. We are not aware that it is ever purchased, in retail, for any other purpose than as a detergent, to clean the tops of boots; in the large way, it is an article of extensive trade with the calico printers. Its salts[326] are likewise employed for various purposes in the arts.