Plant Sanitation. 



392 



vessel, and another man simultaneously dips up and pours in bueketfuls of the 

 milk of lime. The lime solution should be kept well stirred. If only a single 

 barrel is to be made, the materials may be dissolved in the dilution tubs, but if 

 a number of lots are required the materials can be kept in stock solution (see below) 

 and simply transferred by dipping. In preparing very small quantities of Bordeaux 

 mixture, buckets or similar vessels may be substituted for the half-barrel tubs. 

 It is possible for a single operator to dip a bucketful of the bluestone solution 

 and then a bucketful of milk of lime and pour them together into a vessel. It is 

 usually preferable to have a bucketful or so of water in the receptacle into which 

 the solutions are to be poured, but this is not essential. 



The better and quicker way of making up Bordeaux mixture by the barrel 

 consists in placing the two half-barrel tubs on an elevated platform, and then, 

 by means of hose or spigots, allowing the two solutions to flow together into a 

 barrel. This method is more fully described farther on. 



Straining the Materials. — No matter what quantity of mixture is to be made 

 up, it is necessary to strain the materials through a wire strainer. The best type of 

 strainer is made of brass wire, with 18 or 20 meshes to the inch. If all the copper 

 solution is strained and then the milk of lime is strained into the dilution vessels, it 

 will not be necessary to strain the Bordeaux mixture as, on account of its floculent 

 character, it is sometimes more difficult to pass through the strainer than the lime 

 milk. Some very good strainers made of copper are on the market and may be obtained 

 from the makers of spray pumps. One of the best, which can be made at home, is in 

 the form of a box about a foot square, the bottom of which is a rather heavy board 

 (preferably of hard wood) with a hole bored through it, into which a piece of gas pipe 

 \\ to 2 inches in diameter and 8 to 12 inches long is fitted. The box is, of course, open 

 at the top. Fitting just inside this box is a second and lighter box, also open at the 

 top, and having an overhanging strip nailed around the top which supports it. The 

 bottom of this inner box should be made so as to slope at an angle of about 30, and 

 should be made of wire screen. The slanting bottom makes it harder to clog with 

 the spray, and the inner box, being movable, can be inverted and washed in a tub of 

 water. 



METHOD OF PREPARING BORDEAUX MIXTURE FOR LARGE OPERATIONS. 



In large operations stock solutions should always be used, as the time required 

 to dissolve the material is saved. 



Stock Solutions. — These can be prepared of both the copper sulphate and the 

 lime. They may be made by dissolving copper sulphate in water at the rate of one 

 pound per gallon, and lime in the same ratio, although a strength twice as great may 

 be used in warm weather. When stock solutions are on hand it is only necessary to 

 measure off the required quantity of each and dilute with water before mixing. In 

 preparing a stock solution of copper sulphate, a 50-gallon barrel may be filled about 

 two-thirds or three-fourths full of water ; then a sack, or a box with perforations 

 over which copper wire has been tacked, containing 50 lbs. of bluestone, should be 

 suspended in the upper part of the barrel and enough water added to fill the barrel. 

 In from twenty-four to thirty-six hours this material will be entirely in solution, and 

 the sack or box may be removed. A slight stirring will insure the even distribution 

 of the bluestone, after which the solution is ready for use. 



The copper sulphate should be measured in a copper or granite-ware recep- 

 tacle, iron or tin vessels being quickly destroyed by either copper sulphate or Bor- 

 deaux mixture. 



Use of an Elevated Platform. — If possible the dilution tanks should be raised 

 so high on an elevated platform that the mixture can be conducted by gravity 

 directly into the spray tank beneath. If a hillside is available, it is much the most 



