885 



Page 765. Kelhofer (Internat. phytopath. Dinest, 1908, Part 3) has 

 reported some points in regard to the making of Bordeaux Mixture. The 

 effectiveness of the mixture depends not only on the quality of the materials 

 used but also on the proportionate amounts of the two elements and on the 

 method of preparation. 



In regard to the proportionate amounts, it should be emphasized that 

 the copper precipitate loses its physical properties the more quickly and the 

 danger of washing away by rain is the greater the more calcium is used in 

 preparing the solution. According to Kelhofer's experiments, it is further 

 desirable that the copper vitriol solution and the lime milk are mixed when 

 cool and in the most dilute condition possible and, on this account, the 

 copper solution must be poured slowly into the lime milk; otherwise the 

 precipitate assumes a powdery form which conglobates. Although the 

 addition of sugar is to be recommended in general, care must be taken not 

 to use too large amounts since the copper solution thereby may be more 

 easily washed away. At any rate the amount of sugar necessary to make 

 the mixture keep depends upon the amount of calcium, inasmuch as solu- 

 tions prepared with a good deal of calcium need more sugar. Thus, for 

 example, when using i, 2 and 3 kg. calcium, to 2 kg. vitriol to each 100 liters 

 of water, 20, 30 or 40 gr. of sugar have been found necessary in order to 

 protect the copper precipitate permanently from decomposition, i. e. for at 

 least a year. In common usage, where, as a rule, plenty of calcium is used, 

 it is advisable to take on an average 50 gr. sugar for each hektoliter. With 

 this addition the whole amount of Bordeaux mixture needed can be pre- 

 pared at the same time in the spring at the beginning of the season; the 

 mixture will then keep through the summer. 



Page /"/'2. The investigations of Rudolph Friedrich (Ueber die Stoff- 

 wechselvorgange der Verletzung von Pflanzen. Centralbl. f. Bakteriologie, 

 etc. II, Vol. XXI, p. 330) have confirmed the observations of Zaleski and 

 Hettinger that an increase of protein takes place at the wounded place. 

 Besides this, however, Friedrich found that in the storage organs beneath 

 the soil, as well as in the fruits and leaves, a decrease of carbo-hydrates 

 and an increase of acidity (with the exception of bulbs) sets in as a com- 

 mon, secondary phenomenon of the injury. If, with Ad. Mayer, the acids 

 are considered as the products of oxidation of the sugars, then the increased 

 acidity is explained by the more active respiratory need of the injured 

 organ. The decrease of carbo-hydrates will be explained partially by the 

 fact that they are used for protein synthesis. A corresponding decrease of 

 amids or the amido acids may be considered as further reactions to trau- 

 matic stimulus. These substances are used in the construction of the protein 

 molecule. In the potato the smallest starch grains are used up and intro- 

 duce the formation of sugar. 



Page 787. Hedrick, Taylor and Wellington made girdling experi- 

 ments on tomatoes and chrysanthemums (Bulletin 288 of the Agriculture 



