NICKEL SULPHATE. 193 



grammes for the check plants. Aso found manganese chloride, used 

 as a manure in the cultivation of rice, increased the yield 42 per cent. 

 Nagao pointed out this property for sulphate of manganese, and finally 

 M. Fukutome observed that a mixture with manganese sulphate had a 

 superior action on plants to that of these salts used separately. Al- 

 though manganese does not form according to Gossel's researches a 

 plant food, in general the manganese content of cultivated plants is 

 barely appreciable, yet trees, especially pines, contain appreciable 

 quantities; it hastens vegetation and stimulates growth. 



Use. — Peronospora viticola, De By. (mildew of the vine). — Sbrozzi 

 used this salt to combat the mildew of the vine, but the results were 

 negative. Kaserer did not succeed better with 0'5 per cent solutions 

 of borate of manganese. 



77. Nickel Sulphate, NiS0^7H,,0.— Preparation.— Nickel sul- 

 phate is formed by dissolving nickel, its hydrated oxide or its carbonate, 

 in dilute sulphuric acid of 15° B. It crystallizes from its solutions in 

 the hydrated state with 7 molecules of water. 



Properties. — Crystallized nickel sulphate is green ; it dissolves 

 readily in water. Alkalies yield with solutions of nickel sulphate an 

 apple-green precipitate of hydrated oxide of nickel insoluble in water, 

 soluble in ammonia and in carbonate of ammonia. The ammoniacal 

 solution of protoxide of nickel dissolves silk (Schlossbei^ger). There is 

 thus great analogy between the physical and chemical properties of 

 nickel and copper sulphates as between nickel hydrate and copper 

 hydrate. A nickel hydrate bouillie behaves as to solubility in atmo- 

 spheric agents and its adherence like bouillie bordelaise. 



Action of Nickel Sulphate on Plants. — Nickel sulphate, like 

 copper sulphate and other poisonous plants, possesses the property of 

 stimulating the vitality of these plants if absorbed by them in minimum 

 proportion. Eichards treated different fungi and algae growing in 

 nutritive solutions with small quantities of nickel, copper, zinc, and 

 cobalt sulphates, sodium fluoride, lithium nitrate, sodium arseniate. 

 The dose required to stimulate algae is much less than for fungi. By 

 increasing the dose there is an immediate poisonous action on plants ; 

 24^ milligrammes of nickelous oxide used as nickel sulphate in 1 litre 

 of water (2^ parts in 1,000,000) stop the growth of maize and haricot 

 (Haselhoff). Nickel sulphate behaves like blue vitriol in a nutritive 

 solution used to combat the cryptogamic diseases of plants ; it, owing 

 to the infinitesimal quantities absorbed by plants, imparts more vigour, 

 and that in itself gives more resistance to the plant. However, the 

 stimulating etfect of nickel sulphate is not so decided as that of copper 

 salts (x\so, Nakamura, and Suzuki). 



Action of Nickel Sulphate on Parasitic Fungi. — Nickel sul- 

 phate has a very toxic action on parasitic fungi. It much resembles 

 that of blue vitriol, to which it is superior or inferior according to the 

 parasite treated. A 1 per cent solution of nickel sulphate does not 

 kill the uredospores of Puccinia coronata, Cord. 



Use. — Peronospora viticola, De By. (mildew of the vine). — Gallo- 

 way tried, in 1889, nickel sulphate and nickel hydrate against blue 

 vitriol and cupric bouillie. He concluded that its sporacidic and pre- 



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