British Association. 389 



employed as a substitute for feeding the silk-worm — a striking 

 instance of the utility of men of different pursuits meeting and dis- 

 cussing subjects of this nature together. 



On the Luminosity of the Sea, — Mr. Duncan said, that he 

 brought this subject forward more for the purpose of gleaning in- 

 formation than giving it, with regard to this beautiful phenomenon. 

 The communication arose from a conversation which he lately had 

 with a physician residing at St. Leonard's, and he described the 

 appearance which the sea presented, when illuminated by certain 

 animalculflB, with observations. On the 28th October, the sea 

 presented a most splendid spectacle, every wave appearing as a 

 rolling mass of phosphorus, when the gentleman in question obtained 

 some of the water, and 18 hours after, on being put in the least 

 motion, it emitted phosphorescent sparks, which, however, it did not 

 while remaining in a state of quiescence. When the water was still, 

 innumerable disc-shaped animalculae collected on the water, like 

 minute drops of oil, on an average to the number of 60 or 80 on 

 each square inch of water. They become more visible in placing a 

 piece of black silk beneath them, and then they appeared almost 

 white, or some transparent, except at one point which was opaque, 

 and always situated at the margin of the disc, and they differed 

 much in size. The water was kept for six days, at the end of which, 

 the light was still perceptible, in the dark, on agitating the water, 

 but gradually became less brilliant. It has been supposed, that the 

 animalculae float constantly on the surface of the water, and their 

 presence in particular situations depends on certain winds, and cir- 

 cumstances over which they themselves have no control. Reasoning 

 from analogy, he supposed that their appearance did not depend 

 altogether on fortuitous causes ; but, that, as a certain condition of 

 the atmosphere seduces the glow-worm to venture from her obscure 

 retreat, that so these animalculae have been taught to rise only 

 during certain states of their element from the depths beneath. This 

 was the substance of the communication from his friend ; but, what 

 was singular, was that they could not observe any light from 

 animalculae till the water had been shaken ; it, therefore, favoured 

 the supposition, that it was necessary for them to imbibe oxygen to 

 enable them to emit the same. 



Colonel Sykes said, that in tropical countries he had himself seen 

 the animalculae, which were very minute; gelatinous masses, he 

 stated, emit light without being agitated. 



Remarhs on the Cow Fish., or River Cow (^manatusjluviatilis.) 

 By Dr. John Hancock. 



Mr. Rootsey read a paper describing this animal, a specimen of 

 which was exhibited. The animal was now only found in the lakes 

 far away from the European settlements, and the name chosen was 

 very inappropriate. Some authors asserted that the animal frequently 

 weighed 8000 lbs., and measured 28 feet in length, but he (Dr. 

 Hancock) having seen many, and examined them, thought they very 

 seldom exceeded 600 lbs. in weight, and six feet in length. The 

 flesh of the animal is very good, very much resembling veal, very 

 easy of digestion, and the soup made from it was delicious, and equal 

 to turtle, though not so gelatinous ; the flesh woidd also keep 



