226 



Transactions. — Zoology. 



bustible nitrogenous body ; under the microscope it presented traces of an 

 organized structure. 



A careful qualitative analysis was made of a portion of the shell, and, 

 in addition to calcium carbonate, alumina (with traces of iron), phosphoric 

 acid, magnesia, sulphur, potash, and soda, were found to be present ; the 

 latter three were in very small quantity, and no estimation of the amounts 

 was attempted. 



ANALYSIS. 





Moisture driven off at 100° C 



•20 



Carbonic acid 



. . 4005 



Phosphate of alumina, with traces of iron 



•29 



Lime 



. . 53-65 



Phosphate of magnesia . . 



•17 



Phosphoric acid . . 



•59 



Organic matter . . 



.. i-m 



Undetermined, including traces of sulphur, potash, and 



soda -15 



.. 91-02 



1^29 



•17 



•29 



1-98 



. . 4-90 



•15 



•20 



100-00 

 The above results calculated out to the proximate constituents give the 

 following : — 



Calcium carbonate 

 • ,, phosphate 

 Magnesium phosphate (Mg3(Po^)2) 

 Aluminium phosphate, with traces of iron (Al2(Po^\) 

 Lime 



Organic matter . . 



Traces of sulphur, soda, and potash, undetermined 

 Moisture driven off at 100° C 



100-00 

 The amount of organic matter was determined by the loss on ignition, 

 after deducting the carbonic acid and moisture present, thus, — 



Loss on ignition (carbonic acid, moisture, and organic matter) =; 45-15 per cent. 

 Less carbonic acid 40-05 per cent., and moisture -20 per cent. := 40-25 „ 



.*. Organic matter = 4-90 „ 

 This organic matter probably in part consisted of albumen, since both 

 sulphur and soda were present ; the acetic acid solution also, from which 

 the flocculent organic matter had been filtered, became turbid on boiling, 

 thus affording an additional confirmatory reaction for albumen. I much 

 regret that the small quantity of shell at my disposal did not- permit me to 

 prosecute this part of the enquiry further. 



The phosphates of magnesia and of alumina were determined by 

 dissolving out the phosphate of magnesia, by means of acetic acid, from the 

 precipitate containing the mixed phosphates thrown down by ammonia ; 

 the amount of iron present was eo small that it was disregarded. 



