3746 The Zoologist — November, 1873. 



or any statement of its success or otherwise ; but it is due to the 

 memory of this enthusiastic and kind-hearted naturalist, with whom 

 1 had the honour to be personally acquainted, to preserve the 

 record of an ingenious invention. 



Again, two years subsequently, in 1856, the Baron Cloquet, 

 whose ingenuity is well known to all the savans who took part in 

 establishing the Jardin d'Acclimatation at Paris, revived the use of 

 bellows for the purpose of aeration. His instrument had a gutta- 

 percha pipe filled to its nozzle, and at the extremity of this a 

 leaden tube, which extended to the bottom of the aquarium ; the 

 aperture of the tube was covered with wire-gauze, which pulverized 

 in the most complete manner the air forced through it by the 

 bellows; the emission of the air at the bottom of the aquarium 

 would doubtless partially effect the desired object, but not so tho- 

 roughly as Mr. Lloyd's ; for on his plan, presently to be described, 

 the air comes in contact with the water, both in its rapid descent 

 and its deliberate ascent, whereas in the baron's method it could 

 only do this in its ascent. 



Still subsequently, M. Milne-Edwards the younger, son of the 

 great naturalist of that name, invented an apparatus for aerating an 

 aquarium, the peculiar advantage of which was said to be that it 

 required neither manual labour nor any attention ; it is described 

 as working "automatically," thus reminding one of that grand 

 desideratum in mechanics, perpelual viotion : its figure was that 

 of our old hour-glass, consisting of two chambers connected by 

 what may be called a narrow waist. The upper chamber was full 

 of water, the lower full of air ; the water descended by its own 

 gravity from the upper chamber into the lower, expelling the air 

 and driving it into the water of the aquarium, which thus became 

 saturated with air : the operation of emptying the upper chamber 

 took a long time on account of its large size and the smallness of 

 the waist; but when once this was accomplished the entire 

 apparatus swung and reversed itself, in which operation it closed 

 one valve and opened another, and the chamber which now con- 

 tained water being uppermost, the same result look place as before : 

 without seeing the machine I am unable to understand this, so 

 I feel my inability to explain it to others : we all know that under 

 any circumstances the heavy or water-filled chamber would, like a 

 modest gentleman, evince an invincible repugnance to take the 

 uppermost place. 



