308 



SOILS AND FERTILIZERS 



Some of the pieces of apparatus are loaned to the student when 

 needed to perform the experiment ; for these a receipt is taken, and 

 he is credited with the apparatus when it is returned. 



The following are supplied to each student : 



i Crucible Tongs. 



i Pkg. Filter Paper. 



i Test Tube Clamp. 



i Evaporator. 



i Stirring Rod. 



3 Beakers. 



6 Test Tubes. 



i Test Tube Stand. 



i Funnel. 



i Mortar and Pestle. 



No. 



i 



2 



3 



4 



5 

 6 



7 

 8 



9 

 10 



2 Bottles. No. 



i Large Cylinder. 



i Sand Bath. 



i Hessian Crucible. 



i Wooden Stand. 



i Tripod 



i Ring Stand and 3 Rings. 



i Single Clamp. 



i Burner and 2 Ft. Rubber 



Tubing. 

 i Brush. 



ir 

 12 

 13 

 14 



T 5 



16 



17 

 18 



'9 



20 



Directions for Weighing. Place the dish or material to be 

 weighed in the left hand pan of the balance. (See Fig. 51.) With 

 the forceps lay a weight from the weight box on the right hand pan. 

 Do not touch the weights with the hands. If the weight selected is 

 too heavy, replace it with a lighter weight. Add weights until the 

 pans are counterpoised ; this will be indicated by the needle swing- 

 ing nearly as many divisions on one side of the scale as on the other. 

 The brass weights are the gram weights. The other weights are 

 fractions of a gram. The 500, 200, 100 mg. (milligram) weights are 

 recorded as .5, .2, and .1 gm. The 50, 20, and 10 mg. weights 

 as 0.05, 0.02, and o.oi gin. If the 10, and 2 gm. and the 200, the 

 100, and the 50 gm. weights are used, the resulting weight is 

 12.35 g 1T >s. No moist substance should ever come in contact with 

 the scale pans. The weights and forceps should always be replaced 

 in the weight box. Too much care and neatness cannot be exer- 

 cised in weighing. 



General Direction for Laboratory Practice. The student should 

 write up the results of his experiments at the time they are per- 



