bourguignonne

Example Sentences

• "bouillie bourguignonne"
• "99. Carbonate of Copper, CuCO₃ (bouillie bourguignonne).—Preparation.—By adding a solution of a copper salt to a solution of carbonate of soda. To convert 1 kilogramme of blue vitriol, CuSO₄5H₂O, into carbonate of copper, it requires theoretically 453 grammes of dry sodium carbonate or 1146 grammes of soda crystals, Na₂CO₃10H₂O. […] The bouillie bourguignonne designed by Masson to overcome parisitic [parasitic] fungi is merely carbonate of copper suspended in a given amount of liquid [which makes Masson's definition of it different from a typical definition of Burgundy mixture]. It is prepared thus: (1) Dissolve 20 lb. of blue vitriol in 5-6 gallons of hot water, and add thereto after cooling a solution of 8¾-9 lb. of soda ash or 23 lb. of soda crystals, and dilute the whole to 100 gallons with water. (2) Dissolve each compound in 50 gallons of water and mix the solutions as cold as possible at the time of use. The second bouillie is better than the first. To obtain a quite neutral bouillie soda ash must be used, for soda crystals, which normally contain 62·8 per cent of water, are efflorescent, and a neutral bouillie cannot be prepared from them without groping in the dark. Moreover, they always contain larger or smaller quantities of sulphate of soda. The limpid liquid which separates from the blue precipitate after the bouillie has settled should neither be acid nor alkaline; if blue litmus paper dipped in the liquid turns red, carbonate of soda must be added; if red litmus paper turns blue, blue vitriol must be added. Properties.—Carbonate of copper is insoluble in water but soluble in organic acids. The deposit formed on the leaves by spraying with bouillie bourguignonne may become soluble as the cupric hydrate of the bouillie bordelaise and eau celeste, or by the juices transpired by plants, or by water containing carbonate of ammonia or carbonic acid. The amount dissolved being very small, the plant is never in contact with a poisonous amount of soluble copper salt, and bouillie bourguignonne does not burn, except when prepared with a great excess, or with an insufficient amount of carbonate of soda. In making bouillie bourguignonne, not more than 2 kilogrammes of blue vitriol should be used. This quantity is already very strong, and as was the case in other bouillies it has been reduced in modern bouillie bourguignonne to 0·3 per cent. Carbonate of copper freshly prepared by mixing cold solutions of the ingredients is gelatinous, and it is preferably in this form that it should be spread on the leaves to get the maximum adherence and produce the best effect; as it does not preserve this gelatinous condition long, the bouillie must be used immediately after it is made. In fact after eight to ten hours copper carbonate becomes granular, and ends by being converted into a heavy, sandy precipitate, and thus the bouillie loses a portion of its good qualities. This conversion would appear to be accelerated by an excess of carbonate of soda. It already happens when 2·6 kilogrammes of soda crystals are used for 2 kilogrammes of blue vitriol, whilst with 2·3 kilograms, the theoretical amount required, this conversion does not occur until after twenty-four hours. Many bouillies are thus intentionally made with a small excess of blue vitriol, which cannot injure the plant, and which strengthens slightly its action on fungi. If bouillie bourguignonne be made hot, the resulting carbonate of copper is granular and crystalline. Its anti-cryptogamic action is perceptibly inferior to that of gelatinous copper carbonate."