878 SPONGE 



SPONGE. (Spongt, Fr. ; Sc/iwamm, Ger.) Although for a long time it was a 

 disputed point whether the sponge of commerce belonged to the animal or the veget- 

 able kingdom, its animal nature is now well proved, and sponges are regarded as a 

 family of animals forming a class by themselves, Porifera or Spongidts. 



The sponge consists of a soft gelatinous mass, mostly supported by an internal 

 skeleton composed of reticularly anastomosing horny fibres, in or among which are 

 usually imbedded siliceous or calcareous spicula. Sponges are mostly marine ; two 

 or three species only being found in fresh water. In the living state they possess 

 lively colours, and usually grow in groups, upon rock, shells, polypes, Crustacea, 

 and occasionally on sea-weeds. The horny fibres forming the skeletons of sponges 

 are cylindrical and variously united, so as to form a network, often of great beauty. 

 By dissolving the chalk from the sponge-formed fossil in that formation, many very 

 delicate and regular systems of meshes may be obtained. Some beautiful siliceous 

 sponge-skeletons have been brought to this country from the Japanese seas. The 

 gelatinous substance covering the skeleton of sponges resembles the sarcode of which 

 the Amoeba are composed, and appears to consist of minute ' sponge particles,' those 

 lining the internal chambers being furnished with cilia. During life, by means of 

 these, water, entering by the small apertures, or pores, and reaching the channels, is 

 expelled in intermittent currents through the large ' oscula.' Sponges are fixed by 

 a kind of root, by which they hold firmly to any surface upon which they once fix 

 themselves. Sponges may be propagated by division, but more usually by gemmules, 

 which detach themselves from the parent body, and float about until they find a 

 fitting resting-place, when they fix themselves and grow. Sponges adhere firmly to 

 the rocks or other bodies upon which they grow, and are not to be detached without 

 considerable trouble. The inhabitants of the Grecian Archipelago are trained from 

 infancy to dive for these substances. Naturalists distinguish three kinds of sponges, 

 each of which is composed of many species, and these form as many groups or divi- 

 sions. The genus Spongia, which comprehends the sponges of commerce, is the type. 

 The siliceous sponges, Silicea, have the body, or gelatinous portion, curiously strength- 

 ened with siliceous spicula. The calcareous sponges, Calcarea, have spicula of carbo- 

 nate of lime supporting a sub-cartilaginous substance, which is not so soft as the 

 coverings of the other sponges. The horny sponges, Cornea, have no spicula, the 

 body is very porous and elastic, being composed of a fibro-corneous skeleton, the parts 

 of which communicate with each other in all directions. 



The sponges of commerce are obtained from the Mediterranean, Smyrna being the 

 principal mart. Sponges are treated with muriatic (hydrochloric) acid to remove the 

 lime ; they are then dried, well beaten, and again soaked in water, which is frequently 

 changed. Very inferior sponges are prepared for the English market by bleaching, 

 either f#tth hydrochloric acid or chlorine. By this means a very good colour is pro- 

 duced, but the sponge is rendered very rotten. 



An interesting account of the sponge fishery of the Ottoman Archipelago, by 

 M. Bilioti, the British Vice-Consul at Rhodes, appeared in the Technologist, from 

 which the following particulars are abstracted: 'Sponges form the principal 

 article of exportation from this district, and a great portion of them is sent to Great 

 Britain. There are nearly as many different qualities of fine, common, and coarse 

 sponges as there are spots of fishery. The sponges in this quarter are known in 

 commerce by the names of the respective coasts where the inhabitants of the islands 

 of the Ottoman Archipelago dive for sponges. These may be divided into five 

 categories, besides the ordinary classification of fine, common, and coarse. 



Merchants when they purchase sponges take into consideration the form, size, and 

 colour, the quantity of extraneous matter, such as stones and sand, which come out in 

 proportion of their being washed more or less when fished. All this renders the trade 

 very difficult, the more so as (with the exception of Mandruha and Bengazi, which are 

 sold at so much a piece) the sponges are usually sold in -a lump. Latterly the divers 

 have offered their sponges for sale without sanding them (finding that it was no profit 

 to do so), and the merchants again purchase them by weight. 



A French savant, M. Artus, has been experimenting on the bleaching of sponges. 

 Some good sponges were well washed in river-water. Whilst still wet, they were 

 placed in a bath of six parts water and one part commercial hydrochloric acid, and 

 wore allowed to remain until all the carbonic acid gas was discharged. They were 

 then washed again, and afterwards strung together and immersed in hydrochloric 

 acid diluted with 6 per cent, of hyposulphite of soda dissolved in water. The vessel 

 was then closed and left for 48 hours, when the sponges were taken out, washed and 

 dried. M. Artus tried another experiment in which the quantity of hyposulphite of 

 soda was doubled. In a third experiment the sponges were, on removal from the 

 bath, treated with hydrochloric acid, subsequently washed, and then exposed to 

 sulphurous acid gas. The sponges, however, by each of these processes were not 





