181 T H E ANALYST. OCTOBER, 1870. SOCIETY O F ’PUBLIC: ANALYSTS. The next Meeting of this Society will be lielcl 011 Weclncsdny, tlie 19th November, at Burlington House. IODIC ACID TEST 3’0% MORPHIA. BY J. CARTER BELL, F.C.S. IN this note I wish to call tlie attention of chemists to this most unsatisfactory test. I n the chief aiialytical works iodic acid is quoted as an important test for morphia.A solution of iodic acid should be mixed with its volume of sulphide of carbon, there should be no cliange of colour; on adding a small quantity of these mixed liquids to morphia, or its salts, either solid or in solution, the iodine is separated from the iodic acid and dissolved by tlie sulphide, ml~icli sinhs to the bottom, acquiiing tl pink or red colour, varying in its intensity according to the quantity of morphia present.This reaction clis tiiignislies morphia froin the other alkaloids which do not decompose iodic acid.” Professor Taylor seems to lay stress upoii tliis test, because a t tliz c i d of his chapter on morphia, lie meutions it again. I n TVutts’ Dic~iona~y the test is also mentioned. Blyth in his Jlmzcal says :-(( One of the best confirmatory tests is the actioii of iodic acid.’’ He even goes farther, and gives a special note upon this test, but no prec autions.Iu Frcsmiiis’ Qitu7iratice, eiglitli eclition, tlic test is mentioned, but with precautions as to its use, thus :-“ As other iiitrogcnous bodies (albumen, caseine, fibrine) likewise reduce iodic acid, this reaction lins oiily a relative value ; l~oiccccr, if aniuioitin is added after tlie iodic acid, tlie fluid becomes colourless, if the separation of iodide has beer1 caused by other substances, whilst tlie coloratioii becomes mnch more inteiise if it is owing to the presence of morphia.” The foregoing statements do not accord with niy experience : for I find that otller substances, such as ipecacuanlia, guaiacum, will produce the pink colour ; a d , also, that airinionia is n o t able to distinguish between tlic piiili colour of morphia and that produced by other substances.This statement may bc! casily verified by putting into n test tube 2 C.C. of a solution of iodic acid (one part of the acid t o 15 of water), and 2 C.C. of bisulpliide of carbon ; to this mixture is added a izlilligramme of hydroclilorate of morpliiiic, slid, on shaking, tlie beautiful pink colour is communicated to the bisulpliide of carbon ; on adding 5 drops of ammonia, the colour disappears. A few drops of ipecacuanlia wine, in the place of the morphia, will produce tlie same result. Such a doubtful test ought to be banished from all toxicological works ; or, if mentioned, should be qualified by tliis stmate- meiit-that if no pinlr colonr is produced, tlie absence of morpliin may be presumed. Professor Taylor, in his Jfeeclical Jiirispricdence, says