VEUBENACEM. fi5 



similar to prepared chalk, with a dark-coloured gummy matter, 

 and a small quantity of crystalline quartz sand. The following 



is the composition : 



Calcium carbonate 



F 



Tricalcic orthophosphate 

 Quartz sand 

 Organic matter 



Moisture 



« « * * » 



ft A i 



• * • 



• • • 



70-05 

 2-89 

 9-76 



14-30 

 300 



100-00 



com 



carbonate, and the concretion approaches nearer the chalk or 

 limestone formation than that of the apatite or phosphatic found 

 by other investigators. An examination of deposits from other 

 trees might show greater differences than these, but it seems 

 enough has been done to prove that the calcium element forms 

 the base. 



The sand, probably blown up as dust and made to adhere by 

 the organic matter, is a mechanical ingredient. The deposit 

 contained no salts of sodium or calcium soluble in water, nor any 

 ammoniacal compounds ; this would stand to reason, as the heavy 

 rains to which this district is subjected would scarcely leave 

 anything soluble on the trees. 



The scanty amount of lime present in the soil, and the large 

 amount f oimd in the tree, show what an enormous quantity must 

 have been taken up bv the sap. I have shown elsewhere that 

 a full-sized cinchona tree contains about 10 ounces of lime (as 

 slaked lime), not concentrated by abnormal development in one 



place, but 



m 



A teak tree from 



f" 



size and ash contents would hare a mucli larger supply titan a 

 cincliona, and yet, it seems, is able to excrete it in some abun- 

 dance. In wbat manner tkis takes place is not easy to 

 determine. The calcium enters the plant in a soluble fo 

 sulphate. The calcium unites with oxalic and other acids and is 

 precipitated, while the sulphuric acid parts with its sulphur to 



form organic compounds. A wound in the tree is liable to 



III.— 9 



■m 



