My experiments were made by placing half-minim drops on the discs of leaves, or, more commonly, by immersing them in the solutions; and sometimes by both methods. A summary of the results, with some concluding remarks, will then be given. The action of various acids will afterwards be described.
COLUMN 1 : SALTS CAUSING INFLECTION. COLUMN 2 : SALTS NOT CAUSING INFLECTION.
(Arranged in Groups according to the Chemical Classification in Watts' 'Dictionary of Chemistry.')
Sodium carbonate, rapid inflection. : Potassium carbonate: slowly poisonous. Sodium nitrate, rapid inflection. : Potassium nitrate: somewhat poisonous. Sodium sulphate, moderately rapid inflection. : Potassium sulphate. Sodium phosphate, very rapid inflection. : Potassium phosphate. Sodium citrate, rapid inflection. : Potassium citrate. Sodium oxalate; rapid inflection. Sodium chloride, moderately rapid inflection. : Potassium chloride. [page 175]
COLUMN 1 : SALTS CAUSING INFLECTION. COLUMN 2 : SALTS NOT CAUSING INFLECTION.
(Arranged in Groups according to the Chemical Classification in Watts' 'Dictionary of Chemistry.')
Sodium iodide, rather slow inflection. : Potassium iodide, a slight and doubtful amount of inflection. Sodium bromide, moderately rapid inflection. : Potassium bromide. Potassium oxalate, slow and doubtful inflection. : Lithium nitrate, moderately rapid inflection. : Lithium acetate. Caesium chloride, rather slow inflection. : Rubidium chloride. Silver nitrate, rapid inflection: quick poison. : Cadmium chloride, slow inflection. : Calcium acetate. Mercury perchloride, rapid inflection: quick poison. : Calcium nitrate. : Magnesium acetate. : Magnesium nitrate. : Magnesium chloride. : Magnesium sulphate. : Barium acetate. : Barium nitrate. : Strontium acetate. : Strontium nitrate. : Zinc chloride.
Aluminium chloride, slow and doubtful inflection. : Aluminium nitrate, a trace of inflection. Gold chloride, rapid inflection: quick poison. : Aluminium and potassium sulphate.
Tin chloride, slow inflection: poisonous. : Lead chloride.
Antimony tartrate, slow inflection: probably poisonous. Arsenious acid, quick inflection: poisonous. Iron chloride, slow inflection: probably poisonous. : Manganese chloride. Chromic acid, quick inflection: highly poisonous. Copper chloride, rather slow in flection: poisonous. : Cobalt chloride. Nickel chloride, rapid inflection: probably poisonous. Platinum chloride, rapid inflection: poisonous. [page 176]
Sodium, Carbonate of (pure, given me by Prof. Hoffmann).--Half-minims (.0296 ml.) of a solution of one part to 218 of water (2 grs. to 1 oz.) were placed on the discs of twelve leaves. Seven of these became well inflected; three had only two or three of their outer tentacles inflected, and the remaining two were quite unaffected. But the dose, though only the 1/480 of a grain (.135 mg.), was evidently too strong, for three of the seven well-inflected leaves were killed. On the other hand, one of the seven, which had only a few tentacles inflected, re-expanded and seemed quite healthy after 48 hrs. By employing a weaker solution (viz. one part to 437 of water, or 1 gr. to 1 oz.), doses of 1/960 of a grain (.0675 mg.) were given to six leaves. Some of these were affected in 37 m.; and in 8 hrs. the outer tentacles of all, as well as the blades of two, were considerably inflected. After 23 hrs. 15 m. the tentacles had almost re-expanded, but the blades of the two were still just perceptibly curved inwards. After 48 hrs. all six leaves were fully re-expanded, and appeared perfectly healthy.
Three leaves were immersed, each in thirty minims of a solution of one part to 875 of water (1 gr. to 2 oz.), so that each received 1/32 of a grain (2.02 mg.); after 40 m. the three were much affected, and after 6 hrs. 45 m. the tentacles of all and the blade of one closely inflected.
Sodium, Nitrate of (pure).--Half-minims of a solution of one part to 437 of water, containing 1/960 of a grain (.0675 mg.), were placed on the discs of five leaves.