54 



THE GEJTESEE FARMER. 



CHEMICAL 



GRAPES, 



Dr. Chaelks TVetherill, the recently appointed 

 Chemist of the Agricultural Department at Wash- 

 ington, has submitted a report of an examination 

 into the composition of several varieties of Ameri- 

 can grapes. The results are embodied in the fol • 

 lowing table : 



the percentage of ash in the juice, where a suffi- 

 ciency of material enabled tiie determination. 

 Enough ash remains fur a qualitative analysis. 

 Column five einhodies the result of the sugar per- 

 centage in the juice. As ISO parts of grape sugar 

 are equivalent to 92 parts of alcohol, a larger per- 

 centage of alcohol in tiie wine than half the per- 

 centage of sugar in tlie juice is not possible, unless 

 sugar has been added to the juice. The last col- 

 unm contains the percentage of free acid in the 

 juice calculated as if it were dry tartaric acid. 

 Circumstances permitted only nine acid determina- 

 tions, which is to be regretted as the point is an 

 interesting one." 



Fourteen varieties of the grapes were obtained 

 from the September Exhibition of the Fruit 

 Growers' Society at Philadelphia, "We do not 

 know how many bunches of grapes of each variety 

 were obtained, but judging from the remark 

 " enough ash remains for a qualitative analysis," 

 we fear hardly sufficient to give a fair test. 



CHSJacAii Analtbis of Geapes— By Db. Chablbs M. "WKXHEBrLL, chibp cHsjasT, Depabtmbkt of A0BI01TI.TUBE, Was* 



INQTOlf , D. C, OOTOBEB, 1863. 



Ko. 



Sesigiiatlos ot the grapea. 



b5 



2a 



Sw 



c3 



JS-o^ 



go o^ 



Kaabe Philadelphia Exhibition 



Baldwin LeNolr Agricultural Department 



Rebecca do do 



Deveraux do do 



Canby'8 August do do 



Black September do do 



Clinton do do 



To Ealon do do 



Cnepern Charles J. Uhlmann, Washington, D. C. 



Cape Philadelphia exhibition 



Norton's Early Virginia do do 



Diana do do 



Union Village do do 



14 I Montgomery do. 



Caasldy do. 



Herbemont d**- 



Delaware do. 



Marion do. 



Trlmon do. 



Ontario do. 



Elsinbarg do. 



Anna do. 



.do 



.do . 



.do. 



.do . 



.do 



-do 



.do. 



.do 



.do 



79.70 

 82.67 

 80.82 

 73.19 

 70.48 

 T2.60 

 70.08 

 79 62 

 85.83 

 7S.90 

 77.62 

 74.82 

 86.26 

 88.06 



Schnylidii.'cisabella) Mrs. Reese, Dowington, Pa., by Captain DlUer 



Bland, (Catawba) do do do | 



if 



77.64 

 81.69 



1.079 

 1.107 

 1.088 

 1.096 

 1.082 

 1.057 

 1.096 



i.on 



1.079 

 1.065 

 1.089 

 1.085 

 1.043 

 1.017 

 1.087 

 1.080 

 1.077 

 1.071 

 1.055 

 1.0« 

 1.062 

 1.073 

 1.069 

 1.072 



15.87 

 20.36 

 11.83 

 11.55 

 11.70 

 8.95 

 17.07 

 12.63 

 14.12 

 10-45 

 15.90 

 14.87 

 7.73 

 8.40 

 15.41 

 16.73 

 13.41 

 13.25 

 9.87 

 S.SS 

 10.76 

 11.98 

 14.00 

 M.91 



0.926 

 0.933 

 0-514 

 0-803 



(*) 

 1.754 

 1.022 

 0.817 



0.811 

 0.833 



* Not determioed. 



Dr. "Wktherill says: 



"The first column of numbers represents the 

 approximate percentage of juice in the grape. The 

 results were obtained by pressing the weighed 

 grapes in a muslin cloth, and weighing the residue 

 in the cloth without drying it. The third column 

 contains the percentage ot extract or solid matter 

 left by evaporating the juice to dryness, and ex- 

 posing it to a temperature a little above that of 

 boiling water. I think that these numbers are 

 probably too low, as I observed in all of the ex- 

 tracts that a portion of the sugar had been con- 

 verted into caramel. This fact may perhaps ac- 

 count for a discrepancy in the extract and sugar 

 percentages of Ex. 23, 24, Column four exhibits 



In investigations of this kind, too, made for the 

 purpose of ascertaining the amount of juice, sugar, 

 tartaric acid, &c., contained in different grapes, it isi 

 desirable that the specimens should be grown ua- \ 

 der similar conditions. It is not at til probable I 

 that those shown at the Philadelphia exhibition in| 

 September were all of the same degree of ripeness. 

 Some of the varieties are much earlier than others. 

 The Delaware, for instance, might be nearly ripe, 

 while the Diana was almost green. Probably none* 

 of the varieties obtained in September were ripe 

 enough to make good wine. 



