THE CHEMISTRY OF COOKERY. 673 



Generally described, these consist in producing an imitation of the 

 natural salinity of the dry wine by the addition of factitious salts and 

 fortifying with alcohol. The sugar remains, but is disguised thereby. 

 It was a wine thus treated that first brought the subject of the sul- 

 phates, already referred to, under my notice. This, although sold to 

 my friend at a good price, was a concoction of the character known in 

 the trade as Hambro' sherry. It contained a considerable quantity of 

 sugar, but was not perceptibly sweet. It was very strong and decid- 

 edly acid ; contained free sulphuric acid and alum, which, as all who 

 have tasted it know, gives a peculiar sense of dryness to the palate. 



The sulphuring, plastering, and use of Spanish earth, described in 

 my last, increase the dryness of a given wine by adding mineral acid, 

 and mineral salts. In a paper recently read before the French Acade- 

 my by L. Magnier de la Source (" Comptes Rendus," vol. xcviii, page 

 110), the author states that "plastering modifies the chemical charac- 

 ters of the coloring-matter of the wine, and not only does the calcium 

 sulphate decompose the potassium hydrogen tartrate, with formation 

 of calcium tartrate, potassium sulphate, and free tartaric acid, but it 

 also decomposes the neutral organic compounds of potassium which 

 exist in the juice of the grape." I quote from abstract in " Journal of 

 of the Chemical Society " of May, 1884. 



In the French " Journal of Pharmaceutical Chemistry," vol. vi, pp. 

 118-123 (1882), is another paper, by P. Carles, in which the chemical 

 and hygienic results of plastering are discussed. His general conclu- 

 sion is that the use of gypsum in clearing wines " renders them hurtful 

 as beverages " ; that the gypsum acts " on the potassium bitartrate 

 in the juice of the grape, forming calcium tartrate, tartaric acid, and 

 potassium sulphate, a large proportion of the last two bodies remaining 

 in the wine^" XJnplastered wines contain about two grammes of free 

 acid per litre ; after plastering, they contain " double or treble that 

 amount, and even more." 



A German chemist, Griessmayer, and, more recently, another, Kai- 

 ser, have also studied this subject, and arrive at similar conclusions. 

 Kaiser analyzed wines which were plastered by adding gypsum to the 

 must, that is to the juice before fermentation, and also samples in 

 which the gypsum was added to the " finished wine," i. e., for fining, 

 so called. He found that " in the finished wine, by the addition of 

 gypsum, the tartaric acid is replaced by sulphuric acid, and there is a 

 perceptible increase in the calcium ; the other constituents remain 

 unaltered." His conclusion is, that the plastering of wine should be 

 called adulteration, and treated accordingly, on the ground that the 

 article in question is thereby deprived of its characteristic constituents, 

 and others, not normally present, are introduced. This refers more 

 especially to the plastering or gypsum fining of finished wines (Bie- 

 dermann's " Centralblatt," 1881, pp. 632, 633). 



In the paper above named, by P. Carles, we are told that, " owing 

 VOL. XXVI. — 43 



