JULY, 1908*. 



35 



Miscellaneous. 



From the accompanying Plate (not repro- 

 duced) it will be seen that pyrolusite, which, 

 by the way, occurs in such large quantities 

 in South Africa, gave by far the best result, 

 a remarkably healthy plant being produced. 

 No. I., grown with chloride of manganese, 

 also shows considerable improvement in size 

 and quality. No. III. did not give such a 

 result as expected, but the quality is far 

 better than No. IV., containing no manganese. 



Of course, absolute reliance cannot be 

 placed in one trial only, but next year the 

 work will be repeated on a far larger scale, 

 and on the giound itself. 



Note on Manganese Compounds as a 

 Manure. 



Although from the experiments of Kata- 

 yama, Nagaoko and others, there can be 

 little doubt that small additions of man- 

 ganese salts to soils often produce a consider- 

 able increase in crop, especially in legumin- 

 ous ones,* Salomone has shown that large 

 iimounts are decidedly injurious, and that 

 manganic salts are much more injurious than 

 manganous. 



Experiments at Woburn have shown con- 

 siderable benefit by soaking seed wheat in a 

 solution of manganese sulphate containing 

 less than 2 per cent, of the salt before sowing, 

 while barley obtained no advantage by such 

 soaking. Both crops, however, were im- 

 proved by the addition to the soil of about 

 50 or 60 lb. of manganese sulphate per acre. 



The Japanese experimenter, Nagaoko, 

 found that with rice up to 80 or 90 lbs. per 

 acre of manganese sulphate was beneficial. 

 In Dr. Sutherst's experiment the dressings 

 employed would correspond to approxi- 

 mately 22 lbs. of manganese chloride and 

 manganous sulphate, and about 55 lbs. man- 

 ganese dioxide per acre. These quantities 

 are apparently somewhat lower than pre- 

 vious investigators had found the most bene- 

 ficial. With reference to this point, I may 

 mention that I have found appreciable quan- 

 tities of manganese in several samples of the 

 so-called ' ' bats' guano " from caves in the 

 dolomite. 



As to the method by which manganese 

 compounds act upon plants, I have little to 

 add to what Dr. Sutherst has stated. It 

 appears probable that its effects are very 

 similar to those of ferrous sulphate ("green 

 vitriol"), small dressings (say 56 lbs. per acre), 

 of which have long been known to have a 

 decidedly beneficial effect upon many crops. 

 This is apparently due to an increase of 

 chlorophyll production in the plant, though 



* In the case of peas the former investigator 

 found an increase of 50 per cent, in the straw and 

 25 per cent, in the seed by the addition of '015 per 

 cent, of manganese sulphate to the soil, while 

 with barley the total increase was only 10 per cent. 



Griffiths adduced evidence that the iron 

 enabled the plants to develop without such 

 large amounts of potash compounds as they 

 would otherwise require. 



For the present it will be safer to assume 

 that manganese exerts a "tonic" action, 

 but its application to a soil must not be 

 regarded as at all an efficient substitute for 

 the plant food required and usually supplied 

 in commercial mamires. 



In other words, it is probably better re- 

 garded as a medicine than as a food. 



Herbert Ingle, 



Chief Chemist, 

 Transacted Agricultural Department. 



—Transvaal Agricultural Journal, April, 

 1908. 



[In the Plate referred to are the following 

 notes : No. 1, 2 grains manganese chloride ; 

 No. 2, 5 grains manganese dioxoide ; No. 8, 

 2 grains manganese sulphate ; and No. 4, 

 No manganese.] 



LITERATURE OF ECONOMIC 

 BOTANY AND AGRICULTURE, 

 XXXI. 



Rubber Cultivation. 

 Methods op Cultivation and Tapping. 



Collecting rubber. Planting Opin. 

 10. 2. 1900, p. 100. 



Sur un nouveau procede d'extraction 

 du Caoutchouc. Rev. Cult. Col. 

 VI. 1900, p. 304. 



Blatterkautscb.uk. Preyer in Tro- 

 penpfl. 4. 1900, p. 230. 



The tapping of rubber trees in the 

 Charduar rubber plantation, As- 

 sam, 1899. "T- A." Aug. 1900, p. 82. 



A new method of extracting rubber 

 (pounding the bark;. "T.A." Sept. 

 1900, p. 192. 



The Charduar rubber plantation, 

 Assam: results of tapping. "T.A." 

 Jan. 1901, p. 453. 



Das Schneiden der Kautschuk- 

 baume. Tropenpfl. 4. 1900, p. 79. 



A new method of extracting rubber. 

 Rev. Cult. Col. 5. 2. 1900, Ind, 

 Gardening 15. 3. 1900, p. 176, and 29. 

 3. 1900, p. 209. 



L'extraction du caoutchouc des ecor- 

 ces. Rev. Cult. Col, 6. 1900, p. 104, 



Tapping results in Penang. Singa- 

 pore Bot. Gdn. Report 1899, p. 11. 



Vergleichende Zapfversuehe mit 

 Manihot und Kickxia in Misahohe 

 (Togo). Tropenpfl. 1906, p. 382. 



De caoutchouc- guds. Ind. Merc. 24. 

 9. 1901, p. 722. 



