Table 18. — Shape recovery 



Type of sponge 



Number of 

 sponges tested 



Average 



Standard 

 deviation 



Fiducial 

 limits 





25 



Percent 



Percent 

 1.2 



Percent 



Hudson Grass 



99.5 



99.0-100 



Anclote Grass 



2U 



98.1 



2.5 



97.1-99.2 



Mediterranean Bengasi 



25 



91.0 



9.2 



87.2-99.2 



Florida Yellow 



2U 



97.8 



1.6 



97.2- 98.5 



Rock Island Sheep swool 



28 



9U.9 



9.3 



91.3- 98.5 



Inshore Sheep swool 



26 



93.3 



7.9 



90.1- 96.U 



Mediterranean Deepwater 



28 



79.1 



10.0 



75.2- 83.0 



3» The difficulty in cleaning the Grass and the Florida Yellow- 

 sponges is confirmed. 



U. The low absorbency of the Grass sponges is confirmed. The 

 high absorbency of the Bengasi sponges, however, was not known, or 

 at least not publicized in the domestic trade. It is interesting 

 that the Florida Yellow sponges, however, are statistically not any 

 less absorbent. 



5. The low elasticity and shape recovery of the Mediterranean 

 Deepwater sponge, with the Mediterranean Bengasi sponge being close 

 behind in elasticity, are shown. 



6. The high shape recovery of the Hudson Grass sponge, with the 

 Anclote Grass, Florida Yellow, and Rock Island sponges in the next 

 close group, also is shown. 



Field testing . — Originally, it was hoped that a simple field 

 tester could he devised to make use of the important quantitative 

 findings based on wet testing, as described above. If in the future, 

 this test still is thought to be important, it is suggested that a 

 first trial could be made by using a type of pliers that would bear 

 two porous plates and a standardized spring. The spring could be set 

 in notches corresponding to a definite pressure per square inch for 

 the average diameter (in other words, area) of the sponge, and the 

 spring could be cocked with the plier handles. The procedure in 

 this test could be as follows: (1) The sponge is wet in a standard 

 volume of water in a calibrated vessel and placed between the plates. 

 (2) The volume of water is observed in the vessel. (3) The spring 

 is released so that the sponge returns water to the vessel under a 

 standard pressure per square inch exerted by the spring. And (U) 

 The volume of water in the vessel is read again. A table would allow 



U6 



