1916] AGEICULTUEAL CHEMISTBY — AGEOTECHNY. 113 



washed, dried for an hour and a half in a steam drying oven, and weighed as 

 silver sulphid. The sulphuric acid and excess silver nitrate are then determined 

 in an aliquot of the filtrate by adding from 20 to 30 cc. tenth-normal sodium 

 chlorid and from 10 to 15 cc. tenth-normal sodium hydroxid, together with a 

 few drops of phenolphthalein, and titrating with tenth-normal sulphuric acid 

 to the neutral point. To the same solution a few drops of potassium chromate 

 are added, and the excess of sodium chlorid titrated with tenth-normal silver 

 nitrate. 



For calculating the various forms of sulphur the following formulas are 

 proposed : 



Thiosulphate sulphur: f=100X4(a— &).0.0016035=0.6414.(a— 6) ; 

 Sulphid sulphur: s=100X2(25+c—d). 0.0016035— f/2=0.3207(25+c—<J)—f/2; 

 o=cc. tenth-normal NaOH ; b=cc. tenth-normal H2SO1 ; c=cc. tenth-normal 

 AgNOs used in titrating the excess of NaCl ; ci=cc. tenth-normal NaCl; f=thio- 

 sulphate sulphur ; «=sulphid sulphur. 



From the weight of silver sulphid (e) the polysulphid sulphur (p) is cal- 

 culated as follows: 



Ag,S=-7.727.(s+t/2) ; p=100e— 7.727. (s+f/2) 



From these figures the amounts of tetra- and pentasulphid present can be 

 calculated. 



The results of several analyses carried out according to the proposed pro- 

 cedure are submitted. 



Jellies and marmalades from citrus fruits, W. V. Cruess {California Sta. 

 Circ. 146 {1916), pp. 8, figs. 2). — This circular discusses the preparation of jellies 

 and marmalades from citrus fruits. Because of their richness in pectin the 

 citrus fruits are especially suitable for this purpose, either to be used alone 

 or blended with other fruits which are poor in pectin. 



A thermometer and also a hydrometer test for determining the sugar con- 

 centration in the jelly sirup is described. Either of these tests is deemed 

 far more reliable than the usual " sheeting " test. 



Recipes for preparing the jellies and marmalades are included. 



The distillation of apple cider in sugar-beet distilleries, E. Saillaed 

 {Monit. ScL, 5. ser., 6 {1916), I, No. 890, pp. 25-25).— This reports the progress 

 of an investigation carried on with apple and beet products as possible sources 

 of alcohol, which was ordered by the Minister of Agriculture in France. 



Tlie present situation of the question on the role of bacteria in voluntary 

 decrease of acidity in wines, A. M. Krtjpenikov {Trudy Selsk. Khoz. Bakt. 

 Lab., 5 {1914) f pt. 2, pp. 195-220). — In the viticultural regions of Bessarabia, 

 the Don, the Rhine, and the Moselle the grapes are not always fully ripe when 

 used for making wine. Such wines contain large amounts of acid. Artificial 

 means are used to diminish this acidity, such as the addition of water or 

 calcium and potassium carbonates for the neutralization of the acids. This 

 procedure, however, injures the wine. 



To obviate this, experiments were made with various bacteria to determine 

 their effect on reducing the acidity of the wine. The results showed that to 

 decrease the acidity it is necessary to promote a very rapid fermentation with 

 pure cultures of yeast by increasing the temperature of the cellar. The wine, 

 should be kept in contact as long as possible with the yeast, although the first 

 transfusion should not be delayed so long as to injure the wine. The tempera- 

 ture after this operation should not be below 15° C. (59° F.). The residue 

 should be thoroughly mixed so that the bacteria come in direct contact with the 

 wine. The wine should be transfused into uncovered or only slightly covered 

 barrels, allowing some of the residue to mix with the wine. 



