272 UTILIZATION OP MINUTE LIFE. 



as in silk. An elementary analysis of commercial 

 sponge has given, in 100 parts 



Carbon 47-16 



Hydrogen 6*31 



Nitrogen 16-15 



Oxygen 26'90 



Iodine 1'08 



Sulphur 0-50 



Phosphorus 1*90 



Bromine traces 



100-00 



Hence I conclude that the animal matter of sponge 

 belongs to the group which contains fibrine, albu- 

 mine, gelatine, etc., all of which give a per-centage 

 of nitrogen resembling the above. 



Winckler and Eagazzini have both shown that 

 the ash obtained by the combustion of Spongia usta 

 contains slight quantities of bromine. 



These results are certainly not devoid of interest. 

 Both CrookewiVs and Posselt's analyses agree 

 pretty well, and show that sponge contains rather 

 more than 16 per cent, of nitrogen. It is, there- 

 fore, as rich in this element as the most valuable 

 kinds of guano are. 



The common sponge (Spongia offidnalis, L.) is 

 found abundantly in the Mediterranean, and will 

 doubtless be cultivated, one of these days, by the 



