982 



whicli shows, that phosphoric acid had disappeared completely, 

 which stiucl< Verbekk also and of which no other instance is 

 recorded, for even there where a conversion of phos[)hate to car- 

 bonate lias taken place, large quantities of piiosphate were left '), 

 Calcinm-phospiiate, it is true, is readily assimilated by the roots of 

 {)lants, but the analysing influence of circulating waters is much 

 smaller. Besides, the shape of those concretions is quite different 

 from those that are found in the stems of Tectoiia. 



^) Justus Roth. Allgemeine und chemische Geologie 1. Berlin 1879, p. 92—94, 211, 



