_Glycerine._--100 c.c. of the wine are reduced by evaporation on the water-bath to 10 c.c., some pure sand added, and then milk of lime to decided alkaline reaction, after which the mixture is evaporated nearly to dryness. When cold, the residue is thoroughly agitated with 50 c.c. of 96 per cent. alcohol, next heated to boiling on the water-bath, and then passed through a filter. The insoluble residue is repeatedly washed with more hot alcohol, the washings being added to the first filtrate. The solution is now evaporated until it assumes a viscous consistency. The residue is taken up with 10 c.c. of absolute alcohol, and 15 c.c. of ether are added, the mixture being shaken and allowed to stand at rest in a well-stoppered flask until it becomes clear. The solution is subsequently filtered into a tared glass capsule, then carefully evaporated to a syrupy condition over the water-bath, and the residue dried in the steam-oven for one hour, and finally weighed. According to Pasteur, 112·8 parts of grape sugar yield 3·6 parts of glycerine; in natural wine, therefore, the glycerine should amount to about 1/14th part of the alcohol present. _Acids._--The acids in wine consist of acetic, tartaric, malic, tannic, succinic, racemic, formic, and propionic. _Total free Acids._--These are determined by titrating 10 c.c. of the sample with 1/10th normal soda solution, litmus paper or tincture of logwood being employed as the indicator. Wines containing free carbonic acid should be repeatedly well-shaken before making the estimation. The free acids are expressed in terms of tartaric acid (C_{4}H_{6}O_{6}). If sulphuric acid or potassium bisulphate is present, a piece of filter paper will be rendered brittle when immersed in the wine for some time, and afterwards cautiously dried. _Volatile Acids._--The volatile acids are estimated by slowly evaporating 10 c.c. of the wine to the consistency of a syrup, and repeating the titration with 1/10th normal alkali solution. The difference in acidity represents the proportion of volatile acids present, which is stated in terms of acetic acid (C_{2}H_{4}O_{2}). It is evident that the non-volatile acids can be calculated by deducting from the total amount of free acids, the tartaric acid corresponding to the acetic acid found. The proportion of volatile acid in genuine wine varies from 0·3 to 0·6 per cent. According to Dupré, in white wine, one-fourth of the total acidity should be due to volatile acids, and in fortified and red wine, they should not exceed a proportion of one-third.