As frequent references have been made in the body of the Bulletin to methods of analyses and manner of judging adapted by European chemist for beer and wine, I have thought it proper to give some of these methods complete. They represent the conclusions of chemists who have devoted their lives to the study of this branch of work, and may very properly be taken as a guide by those of us who have occasion to follow the same line of work in this country, where beer and wine analysis has as yet had little application.

The translation has been made as literal as possible.

The following are the methods adopted by the Berlin Commission:1

A commission of experts, appointed in the year 1884 by the chancellor of the Empire, to which was intrusted the establishment of uniform methods for the chemical investigation of wine, adopted the following resolutions, which were made public by the Prussian minister for commerce and trade by a decree of the 12th August, 1834, which provides that they shall be rigidly adhered to in public institutions for the examination of foodstuffs, and are recommended to the representatives of like private concerns :

Resolutions Of The Commission For Establishing Uniform Methods For The Analysis Of Wines

Since, in consequence of improper manner of taking, keeping, and sending in of samples of wine for investigation by the authorities, a decomposition or change in the latter often occurs, the commission considers it advisable to give the following instructions :

Instructions For Sampling, Preserving, And Sending In Of Samples of Wine For Examination By The Authorities

(1) Of each sample, at least one bottle (3/4 liter), as well filled as possible, must be taken.

(2) The bottles and corks used must be perfectly clean; the best are new bottles and corks. Pitchers or opaque bottles in which the presence of impurities cannot be seen are not to be used.

(3) Each bottle shall be provided with a label, gummed (not tied) on, upon which shall be given the index number of the sample corresponding to a description of it.

(4) The samples are to be sent to the chemical laboratory as soon as possible to avoid any chance of alteration which, under some circumstances, can take place in a very short time, if they are, for some special reason, retained in any other place for any length of time, the bottles are to bo placed in a cellar and kept lying on their sides.

1 Das Gesetz betreffend den Verkehr mit Nahrungsmittel, u. s. w., p. 184.

(5) If in samples of wine taken from any business concern adulteration is shown, a bottle of the water is to be taken which was presumably used in the adulteration.

(6) It is advisable, in many cases necessary, that, together with the wine, a copy of these resolutions be sent to the chemist.

A. - Analytical methods.

Specific Gravity

In this determination use is to be made of a picnometer, or a Westphal balance controlled by a picnometer. Temperature 15o C.

Alcohol - The alcohol is estimated in 50-100cc. of the wine by the distillation method. The amount of alcohol is to be given in the following way : In 100cc. wine at 15° C. are contained n grams alcohol. For the calculation the tables of Baumhauer or Hebner are used.

(The amounts of all the other constituents are also to be given in this way; in 100cc. wine at 15° C. are contained n grams.)

Extract

For this estimation 50cc. of wine, measured out at 15° C, are evaporated on the water bath in a platinum dish (85mm. in diameter, 20mm. in height, and 75cc. capacity, weight about 20 grams), and the residue heated for two and one-half hours in a water jacket. Of wines rich in sugar (that is, wines containing over 0.5 grams of sugar in 100cc.) a smaller quantity, with corresponding dilution, is taken so that 1 or at the most 1.5 grams extract are weighed.

Glycerine

One hundred cubic centimeters of wine (for sweet wines see below) are evaporated in a roomy, not too shallow, porcelain dish to about 10cc, a little sand added, and milk of lime to a strong alkaline reaction, and the whole brought nearly to dryness. The residue is extracted with 50cc. of 96 per cent. alcohol on the water bath, with frequent stirring. The solution is poured off through a filter, and the residue exhausted by treatment with small quantities of alcohol. For this 50 to l00cc. are generally sufficient, so that the entire filtrate measures 100-200cc. The alcoholic solution is evaporated on the water bath to a sirupy consistence. (The principal part of the alcohol may be distilled off if desired.) The residue is taken up by 10cc. of absolute alcohol, mixed in a stoppered flask with 15cc. of ether and allowed to stand until clear, when the clear liquid is poured off into a glass stoppered weighing glass, filtering the last portions of the solution. The solution is then evaporated in the weighing glass until the residue no longer flows readily, after which it is dried an hour longer in a water jacket. After cooling it is weighed.

In the case of sweet wines (over 0.5 grams sugar in l00cc.) 50cc. are taken in a good sized flask, some sand added, and a sufficient quantity of powdered slack-lime, and heated with frequent shaking in the water bath. After cooling, l00cc. of 96 pet cent. alcohol are added, the precipitate which forms allowed to separate, the solution filtered, and the residue washed with alcohol of the same strength. The alcoholic solution is evaporated and the residue treated as above.

Free acids (total quantity of the acid reacting constituents of the wine). These are to be estimated with a sufficiently dilute normal solution of alkali (at least one-third normal alkali) in 10 to 20cc. wine. If one-tenth normal alkali is used at least l0cc. of wine should be taken for titration ; if one-third normal, 20cc. of wine. The drop method (Tupfel methode), with delicate reagent paper, is recommended for the establishment of the neutral point. Any considerable quantities of carbonic acid in the wine are to be previously removed by shaking. Those "free acids' are to be reckoned and reported as tartaric acid (C4H6O6).