332 THE WEALTH OF THE SEA 



removed from the water, beaten with a club, and 

 squeezed repeatedly under water until all the fleshy 

 matter was removed, leaving only the skeleton. 



A somewhat more scientific procedure is now em- 

 ployed. The live sponges are placed on deck, and, 

 after being killed by continuous treading under the 

 bare feet of the crew, they are strung and then hung 

 over the side of the boat for some time. Then they 

 are thoroughly washed on deck in tubs of sea-water. 

 The cleaned sponges are strung on cords six feet 

 long. The ends of the cord are tied together, thus 

 forming a wreath or bunch. When the bunches of 

 sponges are partially dried, they are sold in lots at 

 auction to the dealers. The wholesalers trim the 

 sponges with sheep shears, removing the irregulari- 

 ties, torn parts, and foreign bodies, such as shells 

 and pieces of coral. They are then graded as to size, 

 color, and quality, and packed in bales for shipment. 



Some sponges are bleached by treatment with a 

 mineral acid, potassium permanganate, and oxalic 

 acid. The bleached sponges are washed in a wash- 

 ing-soda solution to neutralize any acid that may 

 remain, and finally are thoroughly washed in water 

 to rinse out any chemical that may be left. Bleached 

 sponges are somewhat more attractive in appearance 

 but are less durable than those which have not been 

 bleached. 



There are many commercial varieties of sponges. 

 Dealers in different localities may classify sponges 

 differently, but the following varieties are generally 

 recognized as the most important: sheepswool or 



