16 THE HISTORY OF AQUARIA. 



the visitors to the aquarium worked them with their 

 hands, as a sort of amusement in the intervals of 

 pacing about examining the tanks, and the Doctor 

 found the air supply thus administered was sufficient. 

 It is, however, too uncertain a method for other 

 institutions to copy. - 



In fitting up small marine aquaria, the chief 

 difficulty which people found who lived inland was 

 in getting good sea-water. To meet this want, in 

 1854, Mr. Gosse showed how artificial sea-water could 

 be manufactured, by simply adding salts to pure fresh 

 water. The now largely used artificial sea-baths are 

 produced by a small modification of Mr. Gosse's 

 recipe. So successful was the experiment that even 

 great public marine aquaria, like those soon after- 

 wards founded at Hanover and Berlin, were supplied 

 with salt water manufactured after Gosse's fashion. 

 As soon as it was found that no great labour was 

 needed to keep marine and fresh-water animals alive 

 and healthy, in simply aerating the water, or in having 

 properly adjusted aquatic plants, public aquaria were 

 commenced in many of the large towns in Europe. 

 Although these were not of the pretentious character 

 with which we have now learned to associate the 

 name, they did much to develop an interest in na- 

 tural history. Before long there were aquaria at 

 Belfast, Galway, Edinburgh, Scarborough, Weymouth, 

 Boston, Vienna, Hamburg, Cologne, and especially at 

 Havre. Some of them consisted of only one huge 



