Effect of Manganese Compounds 79 



natans ('15 % Mn 3 O 4 ), Acorus Calamus (1/52 % Mn 3 4 ), Alnus incana 

 (trace '73 % Mn 3 O 4 ), Pyrus communis (215 % Mn 3 4 ). Many other 

 plants were mentioned by Wolff as containing manganese. 



Campani (1876) found manganese in ash by a method in which it 

 was detected as phosphate of manganese, and he claimed to be the first 

 to discover manganese in wheat ash. Warden (1878) found traces of 

 Mn 3 O 4 in the ash of opium from Behar. 



Dunnington (1878) detected manganese in the ash of wheat, 

 00144 gm. (as Mn 3 O 4 ?) in 300 grams of " Dark Lancaster " variety, 

 equivalent to '027 % of the pure ash. The ash was exhausted with 

 nitric acid, and after separating the iron the ammonium sulphide pre- 

 cipitate was found to contain manganese, and gave by fusion with nitre 

 and sodium phosphate a violet coloured mass. Andreasch (1878) found 

 slight traces of Mn 3 4 in the flowers of Dianthus caryophyllus, none 

 occurring elsewhere, while in Rosa remontana it appeared in both leaves 

 and flowers. 



Maumene (1884) tested many food plants and concluded that some 

 quantity of manganese is frequently present in potato, rice, barley, carrot, 

 lentil, pea, beetroot, asparagus, chicory, most fruits, tea, and also in some 

 fodder plants, as lucerne, oats, and sainfoin. Bicciardi (1889), Hattensaur 

 (1891) also added to the list of plants proved to contain manganese. 

 Guerin (1897) studied the manganese content of woody tissues. Sawdust 

 was treated with distilled water containing 1 % caustic potash, expressed, 

 and filtered after two or three days. A brown coloured liquid was obtained, 

 which when treated with a slight excess of hydrochloric acid gave an 

 abundant flocculent precipitate. This precipitate proved to be soluble 

 in pure water, so it was washed with slightly acidulated distilled water, 

 and after further purification was analysed. No trace of iron was obtained, 

 but about "402 / Q Mn was found. Guerin regarded the precipitate as a 

 "nucleinic" combination, which he supposed to occur generally in 

 wood and to contain the manganese present in the woody tissues of all 

 plants. 



Schlagdenhauffen and Reeb (1904) detected manganese in a petrol 

 extract of such cereals as barley, oats, and maize, and since inorganic 

 salts of manganese are not soluble in such liquids as ether or petrol they 

 concluded that the manganese must be present in the plant in organic 

 combination, thereby upholding Guerin's view. Loew and Seiroku 

 Honda (1904) give a table of Mn 3 4 in the ashes of certain trees. This 

 is very high in some cases, rising to 11 '25 % in the ash of beech leaves, 

 6'73 % in birch leaves, and 5*48 / Q in chestnut fruits. 



