GENERAL PRACTICE. DISEASES. 249 



soap, 8 ounces; flowers of sulphur, 4 ounces; and 5 gallons of water, thoroughly 

 dissolved and mixed, syringed over expanding blossoms affected with Oidium, so 

 far arrests its progress as to insure the development of the staminate and pistillate 

 organs and secure the sotting of the fruit. Its efficacy, however, depends on the 

 mixture being applied soon enough, and it has the advantage of destroying aphides. 

 Eau Celeste, applied before the buds expand, also destroys aphides, and chermes. 



M. de Breuil says, page 27 of his "Culture of Fruit Trees " : " Soften all the 

 green parts on the weak side of a tree with a solution of sulphate of iron. This 

 solution, in a proportion of 24 grains to a pint of water, applied after sunset, is 

 absorbed by the leaves, and powerfully stimulates their action in drawing up sap from 

 the roots." Thus sulphate of iron invigorates enfeebled trees. Again, on page 38 

 (having regard to the above fact), he says : " The thought occurred to apply the 

 solution to the fruits, and the effect in increasing the size was extraordinary. Apply 

 it only when the fruit is cool; repeat the operation three times, namely, when the 

 fruits have attained the fourth part of their development, when they are a little larger, 

 and again when they are three-parts grown. The solution excites their powers of 

 absorption, and they draw to themselves a large quantity of sap, which would other- 

 wise flow to the leaves, and they become larger fruit." 



This increase in the growth of foliage and fruit, resulting from applications of 

 sulphate of iron, suggests the fungicidal value of this and other sulphates. Elements 

 tending to heal, renew, and increase the growth of impaired tissues render them less 

 vulnerable to fungoid attacks. Such are Bordeaux Mixture, ammoniacal carbonate 

 of copper solution, and sulphate of iron solution. Bordeaux Mixture contains: 

 copper fungi poison; lime which preserves injured tissues from putrescence; 

 and sulphur " food for the protoplasm of vegetable cells" (Griffiths). Sulphate of 

 iron is readily soluble in water. M. Muntz says it "increases the chlorophyll 0-6 per 

 cent." M. de Breuil's solution of sulphate of iron at the rate of 1 pound to 36 gallons 

 of water, is quite safe after the foliage and fruits are a quarter grown, but ounce to 

 a gallon, or 1 pound to 48 gallons of water, is as strong as it is safe to use on smooth, 

 tender foliage, and J ounce to a gallon, or 1 pound to 64 gallons of water on hairy or 

 downy soft growths ; but cultivators must exercise judgment in applying solutions of 

 the sulphates of copper and iron, taking the condition of the foliage and fruit at the 

 time of application into consideration. 



The chief difficulty thus far has been to find a fungicide strong enough to kill mildew 



VOL. i. K K 



