WINES. 355 



sugar, made from corn, is quite different in composition from the Euro- 

 pean article, which is usually made from potato starch, and I do not 

 know that the presence of amyliu has been demonstrated in the 

 American article. Whether the latter contains much dextrin or not 

 depends upon the character of the il glucose " used ; if it is the liquid 

 glucose, I can testify from experience that it contains a considerable per- 

 centage of dextrin; but if it is the highly converted " grape sugar" or 

 solid glucose that is used, probably not much dextrin is introduced into 

 the wine from it. 



Fraudulent wines are frequently made from raisins or dried grapes in 

 France, and, according to French authorities, can easily be recognized 

 by their high percentage of reducing sugar, and left-handed polariza- 

 tion after fermentation. 



The plastering of wines, which is also very extensively carried on in 

 France, consists in adding to the wine or must a large excess of gypsum, 

 or sulphate of lime. 



The sulphuric acid of the lime salt replaces the tartaric acid which is 

 combined with potash, and forms an acid sulphate of potash, while 

 the tartaric acid separates out as tartrate of lime. The operation is 

 said to give the wine a brighter color and to enhance its keeping qual- 

 ities, probably by a mechanical carrying down of some of the albumi- 

 nous matters. Some authorities seem to regard the addition as a par- 

 donable one on this account, but most condemn it. It certainly intro- 

 duces into the wine a salt entirely foreign to the grape and of a more 

 objectionable nature than that which it supplants, viz, the bitartrate of 

 potash. Both Germany and France are in accord as to the limit of 

 sulphuric acid which can be used in a wine, requiring a wine with a 

 content of SO 3 , corresponding to over 2 grams of potassic sulphate (K 2 

 SO 4 ) per liter, to be designated as a plastered wine. This figure affords 

 a pretty wide margin, for the average content of wines, according to 

 most observers, is not over one-fourth of the standard, or .5 grams K 2 

 SO 4 to the liter. 



The determination of the sulphuric acid can be made directly by pre 

 cipitation of the wine with barium chloride, but is much more conveui- 

 entty and rapidly carried out as follows : 



Take 14 grams of pure, dry, crystallized barium chloride, together with 50cc. hydro- 

 chloric acid, and make up to a liter. If lOcc. of wine are used, every Ice. cf this so- 

 lution required indicates a content of 1 gram K 2 SO-t to the liter of wine ; accordingly 

 to several portions of wine of lOcc. each are added, respectively, 0.7, 1, 1.5, 2cc. and 

 more if necessary, the solution heated, and allowed to stand. When cool they are 

 tiltered, and a little more barium chloride added to each test. The appearance or 

 non-appearance of a further precipitate in the ditferent tests will show between 

 what limits the content of SO 3 lies. 



The use of starch sugar is also likely to introduce sulphates into the 

 wine. 



Fortification of wine consists in the addition of alcohol derived from 

 some other source, The alcohol may be added either to the must or the 



