quantity of amygdalin, but it was analysed, and it agreed in every respect with the natural product. Many other natural glucosides are also decomposed by emulsin. These are 1. Salicin into glucose and saligenin, or salicylic alcohol: C6H1105-O-C6H4—CH2OH + H2O = C6H12O6+ HO-CH-CH2OH 2. Helicin into glucose and salicylic aldehyde: CHuO—0—CHẠ–CHO + H,O 5 = CH2O + HO–CH–CHO 3. Phloridzin into glucose and phloretin, or the phloroglucin ester of p-oxyhydratropic acid, by the emulsin of Aspergillus niger (Hérissey) :— C6H1105-0-C6H4-CH-CO-0—C6H3(OH)2+H2O CH3 = CH2O + HO–CH–CH–CO–O–CH3(OH)2 CH3 4. Arbutin into glucose and hydroquinone :C6H1105—O—C6H4—OH+H2O = C6H12O6+C6H4(OH)2 5. Esculin into glucose and æsculetin, or 4, 5-dioxycoumarin : C6H1105-0-C6H2(OH)-CH=CH.H2O + H2O 6. Coniferin into glucose and coniferyl alcohol : 7. Populin into glucose and benzoylsaligenin, only, however, by certain extracts which most probably contain emulsin, e.g. of Aspergillus niger (Hérissey):— C13H17 (C7H5O)O7.2H2O = C6H12O6+ C7H7 (C7H5O)O2 + H2O 8. Glucovanillin into glucose and vanillin : CHO CHO + H2O = C6H12O6 + C6H3-OCHg OH and glucovanillic acid into glucose and vanillic acid. 9. Indican, the glucoside of indigo, is converted by a soluble ferment, according to Bréaudat, into indigo white and indiglucin; the latter, especially in alkaline solution, is oxidised by another ferment to indigotin; in woad, however, according to Beyerinck, isatan is present, which is decomposed by isatase into free indoxyl, which was formerly thought to be present. Indoxyl is considered by Hazewinkel to be an intermediate product in the formation of indigo, and this explains how in some processes indigo red is formed. 10. Daphnin is converted into daphnetin, and piceïn into piceol, and in each case glucose. Hérissey states that the emulsin of almonds decomposes gentiopicrin from Gentia lutea, syringin and phyllirin, and has a slight action upon ononin and helleboreïn; the emulsin from aspergillus, however, acts easily upon these two last glucosides. Among other glucosides which are chemically changed by ferments other than emulsin, the following may be mentioned : 1. Sinigrin, or potassium myronate, the constituent of black mustard seeds, is converted by the enzyme myrosin into glucose, potassium hydrogen sulphate, and allyl sulphocyanate, or mustard oil: C10H18 NS2O10K = C6H12O6+KHSO4 + СзН¿NCS Apparently a molecule of water is not required for this change, but Gadamer states that the glucoside contains a molecule of water with which it crystallises and loses at 100° in a vacuum. This observer finds that allylsulphide, allylcyanide, and carbon bisulphide are produced as secondary products in the fermentation. He considers that sinigrin is the potassium salt of an ethereal sulphate derived from the hypothetical imidoxythiocarbonic acid, in which the three hydrogen atoms are replaced by SO2OK, C¿H1105, and C3H5, thus : C3H5.N: C.(S.C6H11O5).OSOK 2. Sinalbin, contained in white mustard, is decomposed also by myrosin into glucose, sinapin hydrogen sulphate, and oxybenzyl mustard oil : : Gadamer gives the formula C30 H42N2S2O15 + 5H2O to this glucoside, and the change is hydrolytic as in the case of sinigrin. 3. Rubian, discovered by Schunck in 1852, is said by him to be converted into alizarin and other compounds by an enzyme which he has called erythrozyme. This observer thinks that three molecules break down, one giving alizarin; the second giving rubiretin, verantin, and water; whilst the third gives glucose, rubiafin, and rubiagin. 4. Xanthorhamnin is, according to Marshall Ward and Dunlop, decomposed by the enzyme rhamnase into rhamnose, probably also galactose and rhamnin or rhamnetin C48H66O295H,0 = 4C6H1406+2C12H1005 C. and G. Tanret have obtained a trisaccharide, rhamninose, by the action of rhamnase on xanthorhamnin. This carbohydrate yields, on hydrolysis with acids, two molecules of rhamnose and one molecule of galactose, and the glucoside therefore apparently does not contain glucose in its molecule. 5. Gaultherin is hydrolysed by gaultherase, or betulase, into glucose and methylsalicylic acid : : C14H18O8+ H2O = C6H12O6 + C6H4(OH)COOCH, 6. Tannin is hydrolysed by tannase into glucose and gallic acid : C27H22O17+ 4H2O = C6H12O6 + 3C7H605 The compound of tannin with gelatine, tannates, methyl- and phenyl- salicylates, are also said to be changed by this enzyme. 7. A glucoside in Ecballium elaterium is, according to Berg, decomposed by an enzyme (which he has named elaterase) into elaterin. 8. Lotusin, a glucoside obtained by Dunstan and Henry in 1900, is said by these observers to be transformed by an enzyme, lotase, into glucose, hydrogen cyanide, and lotoflavin. Acids convert it into two molecules of glucose, one molecule of hydrogen cyanide, and one molecule of lotoflavin. Lotusin is a lotoflavin ester of maltose cyanohydrin: and the observers point out that amygdalin and lotusin are the only glucosides which yield hydrogen cyanide on hydrolysis. 9. Kolanin, the glucoside of caffeine, yields under the action of a ferment, glucose, caffeine, theobromine, and kola-red; the same products are given by cacaonin. These glucosides are considered by Schweitzer as made up of: (a) kolanin: one molecule of kola-red, three molecules of glucose, and one molecule of caffeine with the elimination of four molecules of water, with the formula C40H56N4O21; (b) cacaonin: one molecule of cacao-red, C17H12(OH)10, Six molecules of glucose, and one molecule of theobromine, with the loss of eight molecules of water, with the formula C60H86015N4. Knox and Prescott, however, do not think that caffeine and kola red are products of one glucoside. We now come to the artificial glucosides, with regard to which so many important facts have been discovered by Emil Fischer. By this investigator not only have derivatives of glucose been prepared, but also of mannose, galactose, maltose, etc. In general, two derivatives are |