Bordeaux Mixture 69 



pounds may be made in this experiment ac- 

 cording to the amount of Hme-water used. 



Procedure. — Weigh out 0.5 gram of 

 copper sulfate or get a solution containing 

 that amount and dilute it to 380 cc. Meas- 

 \xre out either 70, 74 or 84 cc. of Hme-water 

 and dilute it to 380 cc. Mix the two solu- 

 tions. 



Properties of Bordeaux Mixtures; Note- 

 book. 



1. Compare the color of the two mixtures. 



2. Stir them up and allow to stand. Which stays 

 in suspension best? 



3. How much does each mixture settle in 15 min- 

 utes? Is a white scimi to be seen on either prepara- 

 tion? If so which one? 



4. Filter some of the Woburn Bordeaux and add 

 a few drops of potassium ferrocyanide solution to test 

 tube of the clear filtrate. If copper is in solution as 

 positiv ion, in amounts of over 0.002 per cent, the 

 brownish color of copper ferrocyanid should be seen. 

 It may be necessary to look down the colum onto a 

 white background to see the color and it may be well 

 to compare this tube with another containing only 

 water and the same number of drops of ferrocyanid 

 solution. Are any copper ions (Cu+^") in solution? 



NOTES 



The ordinary, or one per cent, Bordeaux 

 is made from 4 pounds of copper sulfate, 

 4 pounds of quicklime and 50 gallons 

 of water. This formula is here reproduced 



