36 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Table I— (cont.). 





Plot. 



Subftance 

 applied. 



Quantity per 

 acre. 



Dilution. 



Price for 

 Calculation.* 



Cost 

 per 

 acre. 



Mineral Salts 



4 



29 



Merc, bichloride 



20 cwt. 



1/500 



35. per lb. 



£ 



43 







24 



Pot. cyanide 



IO"6 



I / II 5 



IS. „ 



59 







41 



>» 



9 >> 



I / I 5° 



IS. ,, 



5° 







46 



f Caustic soda and 



12-4 „ 



1 /100 



25s. per cwt. 



1st 



J 







ivainit 



OO 



1 /20 



70s. per ton 



Coal-iar deri- 



5 



4 



Phenol 



42 „ 



1/40 



is. per lb. 



232 



vatives 





3i 



Black carbolic 



15 » 



230 gal. 



1 / 100 



„ „ „ „ _ li- 

 IS. per lb. 



86 



Proprietary- 



6 



14 



1/80 



say 2S. per 



23 



Disinfectant 





disinfectant 





1/130 



gallon 





Fluids 





39 





120 





13 







10 



T 1 



izai 



335 »> 



T / -A 





33 







43 



>> 



121 



1/144 





12 







15 



Je3'es Pluid 



242 



1/90 



>> 



24 







42 



„ 



Lysol 



121 



1/144 





12 







19 



312 



1/56 



,, 



3i 







26 



>» 



ureoi 



Ib2 „ 



1 /100 





1 0 







33 



20I 



I /3° 





26 







6 



Clubicide 



39 cwt. 



1/40 





39 







44 



»> 



115 gal. 



i/i5° 





11 







45 



Carbosol 



11 =; 



I /i ^O 





j j 







32 



Evans's Soil 



52-5 „ 



1/250 











Sterilizer 









Powders 



7 



34 

 35 



" V.C." 

 "V.N." 



53 c ^t. 

 56 



dry 

 dry 











36 



Vaporite 



14-8 „ 



dry 



^10 per ton 









25 



Soot 



heavy 

 dressing 



dry 







* These are pre-war prices for purchases in small quantities at a time. 



The young tomatos were transplanted into the soil in February 

 and grew normally, with the exception of the plants over the subsoils 

 containing the chromic acid, potassium bichromate, the heavy dressing 

 of mercury chloride, kainit, salt, and bleaching powder. On all of 

 them a crop was produced of course, the produce of that over mercury 

 bichloride being eaten by the experimenters. The chromium sub- 

 stances, nitric acid, kainit, and bleaching powder were not tried after 

 1915. The remarks on the effects of these substances are given later. 

 Photographs of all the plots were taken during the growing season. 



Registration and Interpretation of Observations. 



In the autumn of every year after the whole crop had been gathered 

 the plants were dug up, the soil carefully shaken off the roots, and 

 each root system was inspected for the presence of nodules. The 

 finest roots in the portions of soil were also examined by crushing the 

 lumps so that no nodule was missed. Afterwards the upper layer 

 of the subsoil was examined for nodules and each result was marked 

 on the wall of the bed and on the plan of the greenhouse. 



The roots grown on the various plots were photographed in 1915, 

 but in 1916 and 1917 this was not done. A system of marking the 



