ADAPTATION. 25 



Gris (1850), showed positively the action of sulphate of iron 

 placed around the stump or on the leaves of chlorotic vines 

 in causing the return of the green colour. 



These facts, often contradicted, have been proved indis- 

 putably in recent years. 



Max. Tord, for instance, experimented in a groie soil 

 near Saint-Jean-d'Angely, on ten contiguous plots of identical 

 composition, with many substances; sulphate of iron crystals 

 placed near the stump of the vine, or between the vines, or 

 distributed broadcast at the rate of 4 ounces per square 

 yard; superphosphate and sulphate of potassium; sulphate 

 of iron dissolved in water, at the rate of 4 to 4^ ounces per 

 2 or 2% gallons of water per vine. The applications were 

 made during March. Sulphate of iron in solution in water 

 alone gave positive results. The plot treated in this way 

 showed no chlorosis; the canes attained a normal develop- 

 ment, while all the other plots, without exception, were of a 

 bright orange colour the same as the whole vineyard. Tord 

 draws the following conclusion: 



' ' Sulphate of iron used to check chlorosis is efficacious 

 if applied early (at the end of February or beginning of 

 March) at the rate of 4 to 4^ ounces per vine dissolved 

 in 2 or 2 % gallons of water. 



"Crushed crystals of sulphate of iron, alone, or united 

 with potassic or phosphate compounds, does not produce any 

 appreciable effect, at least during the first year of applica- 

 tion. 



' ' Sulphate of potassium and superphosphate used in 

 the natural state do not give any apparent result. ' ' 



Cazeaux-Cazalet, and many other viticulturists, arrived at 

 the same conclusions. Finally, we have also made experi- 

 ments, the results of which are similar to the above. A 

 Noah vine (a cpage very sensitive to chlorosis) planted in 

 chalky soil was submitted to the following treatment: 

 One row was treated with a solution of 10^ ounces of 

 sulphate of iron in 2% gallons of water placed at the foot of 

 each vine; one row with a solution of 5^ ounces of 

 sulphate of iron in 2% gallons of water placed at the foot of 

 each vine; one row with a solution of io> ounces of 

 crystallized sulphate of iron per vine; one row not treated. 



The application was made in May. After a few days the 

 plants which had been treated with io> ounces of sulphate 

 of iron in solution assumed a very marked green tint, which 



