ENOLOGICAL STUDIES. 



17 



The tabular data on the sugar and the acid content, and the changes 

 in each of these constituents for the four varieties during the seven 

 days covered, are interesting and important. However, the figures 

 would have been much more valuable if the examinations had been 

 begun before the season was so far advanced. Especially is this 

 true of Montefiore and Norton. The following tabular statement 

 gives in condensed form the salient facts as to changes in sugar and 

 acid content of the several varieties during the period covered by 

 the analyses. In all cases the figures given under total sugar are 

 reducing sugars calculated as invert. 



Comparison of sugar and add determinations made on different varieties at different dates, 



1909. 



1 The total increase or decrease in the sugar or the acid content is the difference between the first and the 

 last analysis, regardless of the maximum shown during growth. 



2 Percentage increase of sugar, i<>.s. 



3 Ratio loss of acid to increase of sugar, 1 :5.3. 



4 Percentage increase of sugar, 17. 



s Ratio loss of acid to increase of sugar, 1 : 11.6. 



For the Catawba grapes the results show an important increase in 

 sugar and an equally important decrease in acid. The observations 

 were not continued long enough to be conclusive, but they are of 

 much interest. The harvesting of all of the fruit save the Catawba 

 for vintage purposes interfered with further comparisons after Octo- 

 ber 4. Although the Catawba grapes were not harvested until 

 October 28, 24 days after the last analysis given in the table, at that 

 time (October 28) they contained only 17.17 per cent of total sugar, 

 a rise of 0.27 per cent as compared with the data of October 4, and 

 the acid was 1.217 percent, a rise of 0.151 per cent. The analysis, 



