VOL. LV.] PHILOSOPHICAL TRANSACTIONS. 257 



been over for more than an hour, the stench of sulphur remained so strong in 

 this garret, as ahnost to endanger suffocation. This garret had been for some 

 time used as a lumber-room by the bursar, and, within a few feet of the place 

 where the lightning entered, lay a heap of old iron casements; it came in here 

 with an amazing force, and shivered the side beam of the roof into ten thousand 

 little splinters, scarcely larger than common needles. As there were many 

 boards, shavings, &c. in the room, it is more than probable something might 

 have taken fire, but most fortunately under a large bow wnidow on the s. side of 

 the room were laid carelessly a number of long iron window bars, almost from 

 one end of the window to the other. Tliese saved the room from further damage ; 

 the electrical matter was by them conducted to the corner of the window, and 

 there made a large round hole, and went out of the room to an iron cramp on 

 the outside, about 11 or 12 feet long, at the lower end of which a stone was 

 cut out of the wall by the lightning, and thence it no doubt descended to the 

 street, then quite wet, without further damage. 



XXXL On the Nature and Formation of Sponges. By John Ellis, Esq., 



F. R. S. p. 280. 



Among those animals commonly called zoophytes, we may plainly discover an 

 evident approximation, from the rudest irregularly formed sponge, which is the 

 lowest being yet observed to have the appearance of animal life, to the most 

 beautiful and elegant red coral. The nature and formation of sponges having 

 never yet been thoroughly investigated, every attempt to explain this dark part of 

 nature must give satisfaction to the curious. The intent then of this letter is 

 to convey to the r. s. what we have seen in the experiments made on them at the 

 sea-side; the substance of what has been said on the subject by motlerns as well 

 as ancients; and lastly, to show how nearly they approach to the alcyoniums, a 

 class of beings next above them in the scale of nature, as being one step nearer 

 to the appearance of animal. 



If we consult the. ancients we shall find, that in the days of Aristotle, the 

 persons who made it their business to collect these substances, perceived a parti- 

 cular sensation, like shrinking, when they tore them off the rocks; and in the 

 time of Pliny the same opinion continued of their having a kind of feeling or 

 animal life in them; but after his time no attention was paid to this kind of 

 knowledge, and it still remained a doubt, till Count Marsigli pronounced them 

 vegetable, as he did all the corals, keratophytons, and alcyoniums, &c. After 

 him, it fell to the lot of Dr. Peyssonel, in his inquiries, to discover them to be 

 animals, or rather, as he calls it, the fabric of animals, formed by a species of 

 urtica marina, (see his manuscript which he sent to the r. s. in the year 1752); 

 but finding on re-examining these intricate bodies in sea water at Guadaloupe 



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