272 Frederick Stoicard : 



substances enumerated, for definite time periods ; at the ter- 

 mination of each steeping experiment to wash the treated 

 material, and then to divide it into separate lots, one of which 

 was placed under ordinary dry storage condii ions, a second 

 planted in good garden soil, a third cooked immediately after 

 treatment, and the residue of this last lot at a later interval. 

 In the case of blight-infected material, these subsequent investi- 

 gations were subjected to planting, cooking, storage, and also 

 to " forcing '' tests, in which the treated material was placed 

 under optimal conditions of temperature and moisture for the 

 rapid development of the hibernating blight-fungus. 



Ppeparation of Steep Solutions. 



Ordinary unpuritied table salt (NaCI) was dissolved in tap 

 water, and solutions of approximately 5 per cent., 10 per cent, 

 brines, etc., were prepared. Aqueous solutions of sulphuric 

 acid, boracic acid, phenol, formaldehyde, etc., of approximately 

 the strengths indicated later on were similarly prepared, with 

 ordinary commercial samples of each of these different reagents. 

 The experiments were established by placing the tubers in tall 

 glass cylinders, and pouring in a sufficient bulk of solution 

 until the material was just completely covered. As no effective 

 means of readily checking evaporation at the surface of the solu- 

 tion were available during the course of these experiments, and 

 moreover as it is a difficulty which would present itself in 

 actual practice in other than laboratory experiments, no attempt 

 was made to control this factor. 



Experimental Data. Brine Steeps. 



(a) Blight-free peeled tubers, Victorian mature thick-skins. 

 Entry of the solution into the storage tissue of tubers, 



Tlie lots of peeled tubers (5 each) were steeped in brines of 

 4.2 per cent., 9.32 per cent., and 17.91 per cent., strengtiis for 

 five days (4.2 per cent.) and six days (9.32 per cent, and 

 17.91 per cent.). Specimens of the brine were removed at 

 intervals, conveniently diluted to definite volumes, and estima- 

 tions of their respective chloride contents carried out. 



