70 THE ANALYST. THE ANALYSIS OF WINES. By R. REYSEB.J~ THE author calls the attention of analysts to the following somewhat unpleasant fact :-- An analyticalchemist of good repute analysed some time ago a sample of wine for a wholesale dealer by the usual process, viz., estimation of alcohol, extract, acids, and ash, also by its action on polarized light. The results of the analysis justified him in reporting : There is not the slightest doubt this wine is genuine from a chemical point of view.I n what the improvement consists he does not mention. But whether it consists in plastering, sugaring, colouring, or fortifying, his wine is adulterated. A more complete analysis and estimation of every constituent must be made to form an opinion. The author strongly recommends the complete analysis of the ash.The relative amounts of lime, magnesia, potash, soda, sulphuric acid, phosphoric acid, and silicic acid are more constant i n wines of the aame origin than has generally been beliered. Now the wholesale dealer acknowledges his wine to be an improved one. It now appears that this ordinary process is insufficient. THE COLOUR MEA6UREH.-~’rOfeSSOr Koenig, of the [Tniversity of Pensylvania, has designed a new instrument, which he calls a chromometer for determining the amount of metals in oree.He prepares borax beads, containing known quantities of the metal to be estimated, and notices of what thickness a glass of the complementary colour to the bead must be to make it appear colourless. The coloured (green or red) glass used, is of wedge shape, and is provided with a graduated rack mcivement, by means of which B reading is obtained, that, on referring to a special table, gives the amount of the metal present.By this process an estimation of manganese can be made in 15 minutes. * Correspondenx blatt des Vereines, Analytischer Chemiker, Jahrg. 2, No. 8. .t. Kurze Chemische Hittheilungen v m Prof.Pr, StolbbTHE ANALYST. 71 THE LONDON WATER SUPPLY. DB. TIDY’S annual report on the quantity and quality of the London Water Supply is somewhat more than usually interesting this year, because of the discussion likely to take place in Parliament on the matter. Dr. Tidy adheres to his often expressed favourable opinion as to the general character and quantity of the supply, and he probably brings more figures of reliable analyfies to prove his point than would be available from any other source.It is, of course, greatly to be regretted that the analyses made by Dr. Frankland are not published in such a form that they would admit of direct comparison with those of Dr. Tidy, and we think it is also to be regretted that both gentlemen appear for all practical purposes to ignore the use of the microscope.Surely there is nothing which can so readily throw light on any points, which may otherwise appear mysterious in water analysis, as a careful microscopical examination of the water itself. and its sediment; more especially would this be the case, if in the analyses we are now referring to, Dr. Tidy had given us any statistics of the microscopical appearances, presented by the Thames and the East London waters. The analyses given enable a comparison to he readily made between the unfiltered and filtered Thames water, and the result appears satisfactory. The filtration has been fairly efficient, and the oxidisable organic matter has been fully one-fourth oxidised, notwithstanding a slight increase of chlorine pointing probably to the fact that concentration has taken place.