General Notes. 781 



GENERAL NOTES. 

 Bordeaux Powder for Dust Spraying. 



Owing to the attention which has been lately directed to the 

 possibilit}^ of using Bordeaux mixture in the dry form, it has been 

 considered advisable to place before local growers what is probably 

 the best form of making this powder. The process has been devised 

 by R. M. Bird, Chemist to the Missouri Agricultural Experiment 

 Station, U.S.A. 



The materials required to make about seventy pounds of a stock 

 powder, which can readily be made up to a strength equivalent to the 

 ordinary 6"4"40 liquid Bordeaux, are as follows : — 



Bluestone ... ... ... ... 6 lbs. 



QiiicMime ... ... ... ... 4 lbs. 



Water to dissolve bluestone ... 2 gals. 



Water to slake lime ... ... 2 gals. 



Air slahed lime, sieved ... ... 60 lbs. 



A box about 3x3x3 feet is required with which the material is 

 sifted. A wire sieve with 25 or 30 meshes to the inch should be 

 made to fit the top of the box, and should be provided with a cover 

 to prevent the lime dust from escaping. Another sieve, but with 

 100 meshes to the inch, is also needed. 



A wooden block made of a flat piece of 1 inch or H inch stuft', 

 about 12 inches square, with a handle at right angles to the surface 

 of the flat piece of wood, will help to rub the material through the 

 sieve. 



Two closely woven cotton flour bags, one slipped inside the other^ 

 are needed to filter the blue material. 



Directions for Making. 



1. Break up into small lumps about 70 or 80 lbs. of quicklime, 

 and spread it out so that it will become air slaked. When slaked 

 and perfectly dry sift it through the fine sieve (100 meshes). 



2. Dissolve 6 lbs. of bluestone in 2 gallons of water, 



3. Slake 4 lbs. of good quicklime so as to get a fine powder, and 

 make up to 2 gallons of milk of lime and allow to cool. 



4. Put 60 pounds of the sifted air slaked lime into a shallow box,, 

 one in which the material can be thoroughly worked with a hoe or 

 shovel. 



5. Pour the well stirred milk of Jime and the bluestone solution 

 at the saine time into a third vessel, and stir well till the whole is 

 perfectly mixed, when it will have a deep blue colour and l)e thick. 



6. Pour immediately into the doable flour bag and squeej^e out 

 most of the water. 



