Chemical Composition of (he Calcareous Corals, 253 



view of the results of the several analyses. The relative 

 proportions of organic matter, carbonate of lime, and the 

 complex precipitate of phosphates and fluorides thrown down 

 by lime-water, are first given ; and afterwards the definite 

 composition of this precipitate in the nine species more mi- 

 nutely investigated. 



Carbonate of lime, 94-881 93*297 



Phosphates and fluorides, 0-710 2-450 

 Organic matter, 4-409 4*263 



Pooillopora. PooiUopora, 

 No. 19. No. 20. 



Carbonate of lime, 94*659 93*60 



Phosphates and fluorides, 0*550 1*90 

 Organic matter, 4*791 4-50 



94*143 94*239 93*59 



0-900 0*500 0-50 



4*957 5*261 5*91 



Pocillopora. Pocillopora. Pocillopora. 



No. il. No. 22 (VI.) No. 23. 



95.001 93-848 94*583 



1-450 0-550 1-050 



3-549 5*602 4*397 



Carbonate of lime, 

 Phosphates and fluorides, 

 Organic matter, 



Carbonate of lime. 

 Phosphates and fluorides, 

 Organic matter, 



A portion of the massive shell of a large Chama, treated 

 in a similar manner, afforded for 100 parts the following 

 result : — 



Carbonate of lime, 

 Precipitate by lime-water, 

 Organic matter, 



97*007 

 2-600 

 0-398 



The amount of organic matter is here very small ; while 

 the precipitate by lime-water is large. The examination of 



