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THE OCCURRENCE OF CALCIUM OXALATE IN THE GIDGEE 

 WATTLE (ACACIA CAMBAGEI BAKER). 



By Thos. Steel. 



References in literature to the occurrence of calcium oxalate in plants are 

 numerous, but records of the amounts present are comparatively scarce. A 

 few of the more important of the latter may be noted. In 1877, W. M. Hamlet 

 and C. R. Plow-right (Chem. News, xxxvi., 1877, p. 93; Journ. Chem. Soc, ii., 

 1877, p. 796) drew attention to the presence of oxalic acid in a large number 

 of fungi, tlie acid apparently existing in the free state, as hydric potassium 

 oxalate and as calcium oxalate. Fistularia hepatica (86% water) contained 

 0.08% of total oxalic acid, equal to 0.57% in the dry plant, and equivalent to 

 0.73% calcium oxalate (C204Ca+H-0). 



The presence of the same acid in small amounts in potatoes and malt is 

 recorded by Siewert (Journ. Chem. Soc, 1883, abs. p. 232). Berthclot and 

 Andre (Journ. Chem. Soc, 1886, abs. p. 734) state that they found 13.9% 

 oxalic acid, which is equivalent to 17.8% calcium oxalate, in the roots (dry) of 

 Rumex acetosa (common sorrel). Of the 13.9% oxalic acid, 5.9 was in the 

 soluble state and the remainder insoluble. 



H. G. Smith (Journ. Roy. Soc. N.S. Wales, xxxix., 1905, p. 23) in a com- 

 prehensive paper describes the occurrence of considerable amounts of calcium 

 oxalate in the bark of numerous species of Eticah/ptus, the percentages present 

 varying from 0.08 to 16.66 of C204Ca+Il20 in the dry bark. 



T)ie occurrence of the same substance in cinnamon and cassia barks was 

 recorded by J. Hendrick (Analyst, xxxii., 1907, p. 14) who found from mere 

 traces up to 3.5% in commercial samples and 6.62% in one of Ceylon wild cin- 

 namon. 



J. Otto (Journ. Soc. Cliem. Ind., xxxi., 1912, p. 411) found from 0.4 to 

 0.9% calcium oxalate in the young needles of pine trees, while old shoots con- 

 tained 2.3%i and young larch leaves 0.1%, all in the dry material. 



R. T. Baker "(Journ. Roy. Soc N.S. Wales, li., 1917, p. 435), as the result 

 of microscopic examination, detected crystals of the same compound in the 

 cells of a large number of Australian timbers. 



Further references to various phases of this subject will be found in the 

 collective indices of the Chemical Society and of the Society of Chemical In- 

 dustry. 



F. B. Guthrie (Agric. Gazette N.S. Wales, viii., 1897, p. 868) recorded 

 an analvsis of the ash of the Gidgee or Stinking Wattle (A. Camhagei), show- 

 ing 90.7% of lime (CaO) and 0.40% potash (K2O). 



