38 MANUAL OF GENERAL AGRICULTURE. 



(2) For calcium nitrate substitute 40 cc. potassium 

 chlorid made by dissolving .1 gram in 100 cc. (Save 

 the remainder for V.) 



V. One culture in full nutrient solution minus phos- 



phorous. For potassium hydrogen phosphate sub- 

 stitute 40 cc. potassium chlorid made in IV (2.) 



VI. One culture in full nutrient solution minus potas- 



sium. 



(1) For potassium hydrogen phosphate substitute 

 40 cc. sodium hydrogen phosphate made by dis- 

 solving .1 gram in 100 cc. distilled water. 

 (2.) For potassium nitrate substitute 40 cc. sodium 

 nitrate made by dissolving .1 gram in 100 cc. of 

 distilled water. 



(3) For potassium chlorid substitute 40 cc. sodium 

 chlorid made by dissolving .4 gram in 100 cc. dis- 

 tilled water. 



VII. One culture in full nutrient solution minus calcium. 



For calcium nitrate substitute 40 cc. sodium ni- 

 trate in the proportion .4 gram in 100 cc. distilled 

 water. 



VIII. One culture in full nutrient solution minus mag- 

 nesium. 



For magnesium sulphate substitute 40 cc. sodium 

 sulphate made by dissolving .1 gram in 100 cc. dis- 

 tilled water. 



IX. One culture in full nutrient solution minus sulphur. 



For magnesium sulphate substitute 40 cc. magne- 

 sium chlorid made by dissolving .1 gram in 100 

 cc. distilled water. 



X. One culture in full nutrient solution minus iron. 



For ferric chlorid substitute 40 cc. sodium chlorid 

 made by dissolving a trace in 500 cc. distilled water. 



Place the covers over each of the ten tumblers and 

 tie them securely in place. Punch ten holes in each cover 



