CORNELL UNIVERSITY EXPERIMENT STATION BULLETINS. 309 



9. The insecticidal value of Paris ^reen when used with the Bordeaux 

 mixture was greater than that of London purple when similarly applied. 



10. More applications are required during a wet season than during a 

 dry one; during wet weather they should be repeated every seven to ten 

 days. 



11. The results obtained this season from the application of a combina- 

 tion of the Bordeaux mixture and Paris green or London purple show that 

 the use of such a combination is valuable and practicable for the treatment 

 of the apple-scab fungus and the apple-worm, even in a wet season. 



12. The apple-scab is found in all regions in the United States from 

 which reports have been obtained. 



18. It is probable that none of our commonly cultivated apples are in 

 all seasons free from scab. 



14. Some varieties are much more subject to the disease than others. 



15. In the preparation of the Bordeaux mixture, 13.21 parts of slaked 

 lime are equivalent to 10 parts of quick lime. 



16. More copper appears to remain in solution when slaked lime is 

 nsed than when the lime is fresh. 



17. The quantity of copper remaining in solution diminishes rapidly 

 as the liquid is allowed to stand. 



18. The action of heat is favorable to the decomposition of 'copper com- 

 pounds remaining in solution in the Bordeaux mixture. 



19. The copper is precipitated in the Bordeaux mixture in the form of 

 hydrate, basic sulphate, and the double basic sulphate of copper and 

 calcium. 



20. It is probable that the precipitated copper compounds are affected 

 by the carbonic acid gas of the atmosphere. The solvent action is particu- 

 larly strong when the copper is in the form of the basic sulphate. 



E. G. LODEMAN, 



Assistant in Horticulture. 



SUNDEY INVESTIGATIONS OF THE YEAR. 



THE DETERMINATION OF SUGAR IN THE TOMATO. 



This determination requires some special precautions; the possible 

 action of the organic acids present, on jjolarized light, precludes the use of 

 the polariscope. and the possible action of other reducing substances than 

 sugar on the Fehling solution is likely to render the results by this method 

 too high. 



These possibilities may perhaps account for the different results 

 obtained by different analyses of the sugar in this fruit, although it is true 

 that there may be wide variations in the actual proportion of sugar in dif- 

 ferent varieties. 



