SPONGIA OFFICINALIS. 



Sponge is found chiefly in the Mediterranean and Red 

 Seas. In some of the islands of the Archipelago the inhabit- 

 ants are trained from infancy to dive for sponges, which are 

 generally found attached to the bottom of rocks, to which they 

 adhere by a very broad base. When the sponge is brought 

 on shore, it is immediately squeezed and washed to get rid of 

 the gelatinous matters ; otherwise putrefaction speedily ensues. 



In commerce two kinds of sponge are met with, which are 

 respectively known as Turkey and West- Indian. 



The Turkey sponge is imported from Smyrna, and is con- 

 sidered the best. It occurs in cup-shaped masses of various 

 size. Its texture is much finer than the West-Indian kind. 

 By the aid of the microscope, it has been discovered that it 

 consists of two species of Spongia, not distinguishable from 

 each other by the naked eye. One of these is characterized 

 by the presence of a beautiful branched vascular tissue, which 

 surrounds, in great abundance, nearly every fibre of its struc- 

 ture, and is inclosed in an external membrane or sheath. In 

 the other, and most common, kind of Turkey sponge, no vas- 

 cular tissue has yet been discovered. 



The West-Indian sponge is found in the Bahama Islands, 

 whence it is commonly known as Bahama sponge. Its forms 

 are more or less convex, with projecting lobes. Its fibre is 

 coarser. Its tissue has but little cohesion, and hence this kind 

 of sponge is commonly regarded as rotten. It consists of one 

 species only of Spongia. 



CHEMICAL AND MEDICAL PROPERTIES AND USES. 



SPONGE when first taken out of the sea has a strong fishy 

 odor. Its color varies from pale to deep brownish-yellow. It 

 often contains stony or earthy concretions, which are found to 

 consist principally of the carbonates of lime and magnesia. 

 Shells are also found in sponge. Various marine animals 

 pierce and gnaw it into irregular holes. 



Spongia qfficinalis is the dry skeleton of the animal, from 

 which the gelatinous flesh has been removed. When de- 

 prived of stony concretions, &c., found in the interior of the 

 mass, it is soft, light, flexible, and compressible. When burnt, 

 it evolves an animal odor. It absorbs water, and thereby 

 swells up. Nitric acid colors it yellow. Liquor potassae dis- 

 solves it. The solution forms a precipitate on the addition 



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