174 



On the Manganese Content of Transplanted Tumours. 

 By F. Medigreceanu, MJX 



(Communicated by Sir J. R Bradford, K.C.M.G., Sec. B.S. Received 

 November 21, 1912,— Read January 23, 1913.) 



(From the Laboratory of the Imperial Cancer Eesearch Fund.) 



The occurrence of manganese in plants is well known. Its quantitative 

 distribution and biological significance have been carefully studied from 

 many points of view. A few examples of the more recent, especially experi- 

 mental work, illustrating some of the biological properties of this metal, may 

 be mentioned. Bertrand* showed that there exists a close relationship 

 between the activity of vegetable oxydases and the amount of manganese 

 present. In a series of very exact experiments with Aspergillus niger, the 

 same author demonstrated that the presence of manganese is necessary to 

 the formation of conidia of this mould.f and also that the rapidity of its 

 growth may be largely influenced by the quantity of manganese added to the 

 culture medium.^ 



The study of manganese in animals is far less advanced than in plants. 

 Since the food-stuffs contain manganese, it is obvious that this element is 

 continuous^ introduced into the animal body. The detection of manganese 

 in animal tissues has been the subject of repeated investigation during the 

 last 70 years. The conclusions, however, which the earlier authors have 

 drawn are very contradictory, undoubtedly attributable mainly to the 

 insufficiency and the defects of the methods and the technic used for the 

 detection and estimation of this element. § 



Recently Bertrand and Medigreceanu applied Bertrand's colorimetric 

 method for estimating the manganese in organic substances|| to an extensive 

 analytical study of this metal in normal animals. By means of this method 

 manganese can be estimated even when present in very small quantities, 

 2/1000 mgrm., and with an error not exceeding 10 per cent. 



Manganese was thus found to be a normal constituent of the organism 



throughout the animal kingdom.1T The invertebrates usually show relatively 



* G. Bertrand, ' Comptes Eendus,' 1897, vol. 124, p. 1032. 

 f 'Bull. Soc. Chim. France,' 1912, Ser. 4, vol. 11-12, p. 494. 

 t Ibid., p. 400. 



§ See Bertrand and Medigreceanu's article, 'Bull. Soc. Chim. France,' 1912, Ser. 4, 

 vol. 11-12, p. 656. 



|| ' Bull. Soc. Chim. France,' 1911, Ser. 4, vol. 9, p. 361. 



IT See Bertrand and Medigreceanu, ' Comptes Eendus,' 1912, vol. 154, pp. 941, 1450 ; 

 1912, vol. 155, p. 82. 



