340 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



der will control the disease if used as directed. Coarse powders, how- 

 ever, must be used in much greater quantities and are more difficult to 

 apply properly. The absolute purity of the sulfur is of little impor- 

 tance, provided there is no large adulteration with inert and useless 

 substances such as gypsum. 



Many samples of sulfur were received at the Experiment Station 

 during the past year and examined. Most of these samples were sent 

 by grape growers. They were all found to be practically pure and 

 unmixed. In the important matter of fineness, however, they differed 

 widely. Two or three of them were so coarse as to be almost valueless 

 for sulfuring vines. (See fig. 16, Sulfur No. 8.) A few were very good 

 and most of them were passable. The prices quoted by the senders 

 were little indication of the value of the samples. Some of the cheapest 

 were of excellent quality for the purpose (see fig. 15, Sulfur No. 16), 

 and some of the most expensive were among the worst (see fig. 16, 

 Sulfur No. 8). This shows the need of a careful examination before 

 purchasing. 



Some of the results of our examinations are shown in the following 

 table : 



SAMPLES OF SULFUE KECEIVED AND EXAMINED BY THE STATION 



IN 1906. 



No. 

 30 



Oy 



3 



20 

 19 

 28 

 26 

 15 

 24 



6 



29 

 13 

 18 



4 

 16 

 31 

 23 

 25 

 10 

 17 



5 

 21 

 27 

 12 



1 



7 



2 



11 

 14 



8 



Sublimed, very fine, no coarse material. 



Sublimed, very good, very little coarse material. 



Sublimed, very good, some coarse material. 



Sublimed, very good, some coarse material. 



Sublimed, good, but with many large grains. 



Sublimed, good, but with considerable coarse material. 



Sublimed, good, but with considerable coarse material. 



Sublimed, good, but with some coarse material. 



Sublimed, fair, about one-third of coarse material. 



Sublimed, fair, but some coarse angular material. 



Sublimed, fair, with considerable coarse material. 



Sublimed, fair, with considerable coarse material. 



Sublimed, with much medium coarse material. 



Sublimed, with much coarse material. 



Ground, good, with little coarse material. 



Ground, good, with about one-third coarse material. 



Ground, good, with about one-third medium material. 



Ground, fair, about one-half fine material. 



Ground, good, except for some large particles. 



Ground, good, but considerable coarse material. 



Ground. 



Ground, fair, about one-half fine material. 



Ground, fair, about one-half fine material. 



Ground, much coarse material. 



Ground, much coarse material. 



Ground, fair, much coarse material. 



Ground, coarse. 



Ground, poor, very little fine material. 



Ground, very poor, hardly any fine material. 



Ground, principally large particles. 



