160 INTERNATIONAL CONGRESS OP VITICULTURE 



Using the above criteria in the study of the three types of Bordeaux 

 mixture met with in practice, to wit, "acid" Bordeaux mixture, "neutral" 

 Bordeaux mixture, and alkaline or basic Bordeaux mixture, I have attempted 

 to show in how far these several washes meet the requirements and conclude 

 as a result of this conspectus as follows: 



I. "Acid" and "neutral" Bordeaux mixtures are less injurious to the 

 grape than alkaline washes. 



II. The toxic value of the unit copper in "acid," "neutral" and alkaline 

 Bordeaux mixtures is the same. 



III. The unit copper in "acid" and "neutral" Bordeaux mixtures is more 

 effective when immediate action is required than the unit copper in alkaline 

 washes. 



IV. Alkaline Bordeaux mixtures are more adhesive than "acid" or 

 "neutral" washes. 



v SULPHUR FUNGICIDES.*" 

 By GEO. P. GRAY, 



Chemist, Insecticide and Fungicide Control Laboratory, University of 

 California, Berkeley. 



The honor of a place on your program was accepted with some reluc- 

 tance as it was felt that the subject of sulphur fungicides could be far better 

 discussed by one of more practical training and experience. Of recent years, 

 however, the chemist is finding an increasing number of opportunities for 

 usefulness in nearly every branch of human activity. From time to time 

 he has been called upon to contribute his share toward the solution of some 

 of the vexing problems arising in the control of insects and fungi. The 

 examination of materials incident to the administration of the insecticide 

 and fungicide laws of the United States and of a dozen or more states is 

 largely a chemical problem. There has thus been created, especially in the 

 United States, an absolute necessity for a more comprehensive knowledge 

 of the composition and properties of insecticides and fungicides. As a 

 natural consequence, a bond of common interest has resulted between the 

 viticulturist, entomologist, plant pathologist, horticulturist, and chemist. 



In view of the preceding remarks there is offered a chemically flavored 

 discussion of the different kinds of sulphur and of the composition and prop- 

 erties of some of the sulphur fungicides which might be of interest to viti- 

 culturists. 



It is thought that such a discussion may be an aid toward a more com- 

 plete understanding of these materials and of their relative merits for the 

 uses to which they may be put to meet various conditions. 



The paper is not presented with the intention of offering advice on any 

 phase of viticultural practice nor to recommend any particular substance or 



