CHEMICAL COMPOSITION OF AMERICAN GEAPES. 19 



The climate and soil conditions of the Virginia Piedmont are so 

 different from those of the northern grape belt that it seems best to 

 ]> resent the results for this district in a separate table. It is intended 

 to extend the investigation of the composition of grapes grown in the 

 Atlantic Coast States so as to cover the territory more thoroughly 

 and to secure a larger number of samples. The data here presented 

 are not sufficient to warrant conclusions, but they are interesting 

 and show the possibility of producing a very high quality in at least 

 ; some of the black grapes grown in this section. 



The samples analyzed at the Stonehenge Laboratory were obtained 

 through the courtesy of Mr. A. Russow, of the Monticello Wine Co., 

 and were taken by him from the fruit brought to the wine cellar at 

 vintage time. It was endeavored to make the sample represent the 

 crop as delivered. 



For 1908 only samples of Norton were obtained. These show a 

 very high average sugar content and an average acid content of less 

 than 1 per cent. This is certainly a high quality and warrants the 

 statement that such a juice needs very little change in composition 

 for wine making. The maximum sugar content found of 22.34 per 

 cent, with 0.902 of total acid, is phenomenal for a strictly American 

 grape. A comparison of the three years' results on Norton shows 

 that the same vineyard has in each year yielded the maximum 

 quality, the average for the three years being above 22 per cent of 

 sugar and 8 per mille of acid (i. e., per thousand, or 0.8 per cent). 

 In several instances the sampling of the Norton grapes covers a 

 period of from four to seven days, yet there is no marked difference 

 shown in composition. The question of the changes in percentage 

 of acid and sugar in the grapes grown in this district needs a thorough 

 investigation. 



During 1909 and 1910 the sampling of several crops of Concord 

 grapes also covered a period from four to seven days, and decided 

 improvement was shown in some of these crops during this tune, 

 while in other cases it was slight. The sampling of several crops of 

 Ives for like periods shows no decided results in favor of the later 

 pickings, and in some cases a deterioration is indicated. These 

 data are by no means to be accepted as proof that the crops actually 

 deteriorated. The question needs a careful investigation of reserved 

 vines, which can be studied for a much longer period, before it can 

 be definitely answered. In the opinion of the writer none of the 

 results for Concord and Ives show the quality which may be produced 

 by thoroughly maturing these varieties. Table IV (p. 35) presents the 

 average data obtained on these Virginia grapes. 



