SPONGE, is a cellular fibrous tissue, produced by small animals, almost im perceptible, called Polypi by naturalists, which live in the sea. This tissue is said to be covered in its recent state with a kind of semifluid thin coat of animal jelly, susceptible of a slight contraction or trembling on being touched, which is the only symptom of vitality displayed by the sponge. After death this jelly dis appears, and leaves merely the sponge ; formed by the combination of a multitude of small capillary tubes, capable of re ceiving water in their interior, and of becoming thereby distended. Sponges occur attached to stones at the bottom of the sea, and abound particularly upon the shores of the islands n the Grecian Archi pelago. Although analogous in their origin to coral, sponges are quite diffe rent in their nature ; the former being composed almost entirely of carbonate of lime, while the latter are formed of the same elements as animal matters, and afford on distillation a considerable quan tity of ammonia.
Hittite sulphuric acid has been recom mended for bleaching sponges, after the calcareous impurities have been removed by muriatic acid. Chlorine water answers better.
The sponges of commerce are usually prepared before they come to the market, by being beaten and soaked in dilute mnriatie acid with a view to bleach then, and to dissolve any adherentyortions of carbonate of lime. Three kindi are found commonly in the market and known as the Turkey ; the variety of the same, which is very rare ; and the West Indian. On exaniiniug the living sponge of com merce with a power of about 500 linear, the fleshy matter will be distinctly ob served, having in its interior gemmte, which are considered to be the young. These are occasionally given off from the mass of living matter. The greater por tion of the nines of sponge consists of small cylindrical threads or fibres, various in size. The spieulm are not found with in these, but in the large and flattened fibres, and varying in number from one to three or more, imbedded in their sub stance. Sometimes one spienlum pro.
jects n half or more from the side of the fibre, and is then only covered with the animal matter at the base, or half way up. The fibres of the West Indian species of sponge have been clearly proved to be solid. In the rare variety of Turkey sponge, the fibres are pos sessed of vessels which anastomose in various directions, differing much in size, and not imbedded in horny fibre, but in a separate sheath. This true vascular tissue performs very important functions in the economy of the animal during life. In some of the tubes of sponge have been observed small globules, the largest of which measured the 1686th of an inch, and the smallest the 50,000th of an inch. They were accidentally perceived to move from right to left.
The rapid strides made in sponging within the Bahamas, since the year 1847, appear almost incredible. Vast quanti ties of sponge may be seen covering fences, yards, and housetops, where it is left to dry, after having been previously buried (in order to kill the zoophyte which inhabits it) and washed. It is afterwards divested of the fragments of rocks which adhere to it, pressed and packed in bales, averaging 300 lbs. weight, each, for the London market, whilre it is manufaetured into cloth hats, dm., and converted to many useful purposes. We are informed that it has recently be come the medium for poultices to wounds instead of cloth. From the 1st January to June 30th, of the year 1849, there were exported nearly1000 bales of sponge, of the value of at feast 25 dollars each— $25,000. On the let of January, a very small stock of sponge was on hand, while on the 30th June every dealer in this article had a large stock; therefore, ns it is a cash article, there must have been paid to the crews employed in this trade at least 40,000 dollars.
The Mediterranean at one time furnish ed all the sponges used in Europe, and the very finest are yet fished up around the Isles of Greece. Our finest sponges sell at a very high price.