P OP TJLAR MIS CELL ANY. 



57i 



Musical Fishes. Cases of peculiar sounds 

 being heard at sea and ascribed to fishes 

 are not rare. Lieutenant White, of our na- 

 vy, relates that, when at the mouth of a river 

 in Cambodia in 1824, he and the crew of his 

 vessel were struck by hearing extraordinary 

 sounds, like a mixture of the bass of an or- 

 gan, the ringing of bells, the guttural cries 

 of a large frog, and the tones of an enor- 

 mous harp, which they heard around the 

 bottom of their vessel. The interpreter said 

 they were produced by a troop of a kind of 

 fish. Dr. Buist, in 1847, told of a party in 

 a boat near Bombay, who heard sounds not 

 unlike the others, which the boatmen said 

 were produced by fish. Similar sounds were 

 reported two years afterward as having been 

 heard from beneath the water at Vizaga- 

 patam. Sir J. Emerson Tennent heard like 

 sounds from the Lake of Batticaloa, in Cey- 

 lon, and the natives said that a shell made 

 them. A correspondent of the " Field," in 

 1867, alleged that the vessel in which he 

 was at Greytown, Nicaragua, was haunted 

 at night by these sounds. A similar ac- 

 count, probably of the same occurrence, is 

 given by Mr. Dennely, in "Nature " of May 

 12, 1870. Another correspondent of the 

 " Field " told of sounds " produced by fish- 

 es " which he heard in the Tavoy River. 

 A review of all the accounts shows that the 

 sounds were nearly always heard in ships at 

 sea, though Canon Kingsley once heard them 

 at Trinidad from the shore ; that they are 

 most commonly heard in tropical regions, but 

 sometimes in the temperate zone ; that they 

 have been noticed along an extensive line of 

 coasts, American, European, and Asiatic, 

 northern and southern ; that they are invari- 

 ably heard at night ; and that they are most 

 generally heard near the mouths of rivers. 

 Dr. Dufosse, who has made the production 

 of sound by fishes a special study, says that, 

 while many fishes can make themselves 

 heard, there is a great variety in the manner 

 in which the noises are evolved. Some- 

 times they proceed from the movements 

 or friction of the pharyngeal bones, or the 

 vibration of the muscles of the swimming- 

 bladder. In the latter way a gurnard pro- 

 duces nearly an octave of notes. The males 

 of the genus Ophidium are provided with 

 a drumming apparatus, consisting of bones 

 and muscles developed in relation to the 



swimming-bladder. The sounds made by 

 the Umbrinas of the Mediterranean have 

 been heard from a depth of twenty fathoms. 



Action of Acids ou Tin - Ware. Mr. 



Francis P. Hall reports the results of ex- 

 periments on the action of vegetable acids 

 acetic, tartaric, and citric acids on lead 

 and tin. The results were rather negative 

 in their tendency, and seem hardly to bear 

 out the assertions that are made respecting 

 the danger of lead-poisoning from tinned 

 goods. The most danger is from the sol- 

 der, and from the action of the acids on 

 the tin itself. The corrosion does not ap- 

 pear to increase as regularly as is supposed 

 with the strength of these acids ; but it was 

 found that corrosion, in the case of canned 

 fruits, takes place very rapidly after the can 

 is opened, so that a can when opened should 

 be emptied at once. Mr. Hall's analyses of 

 bright tin-plate failed in every case to show 

 enough lead impurity to justify the charge 

 of intended adulteration, even in the worst- 

 looking ware from the five -cent stores. 

 Tcrne plate, used for roofing, is known to 

 contain large quantities of lead, but no one 

 with his eyes open is ever likely to buy it 

 for genuine tin. Tin-foil, which is used for 

 enveloping various kinds of food, is in some 

 cases pure tin, in other cases heavily adul- 

 terated. Specimens used for wrapping dif- 

 ferent kinds of compressed yeast were pure. 

 The worst specimen (89'87 per cent lead) 

 was embossed, and on a very fashionable 

 cake of chocolate. 



German Explorations in Africa. The 



Germans claim the honor of having done 

 the most after the English for the explora- 

 tion of the interior of Africa. The trading 

 posts of the Hamburg merchants on the 

 east coast have long exercised a civilizing 

 influence there. To German missionaries 

 are due the first important discoveries that 

 were made in that region, viz., the discovery 

 of Mount Kilimanjaro by the missionary 

 Rebmann, in 1848; that of Mount Kenia 

 by the missionary Krapf, in 1849; and the 

 execution of a map of the country, showing 

 the Ukerewe Lake, by Rebmann and Er- 

 hardt, a work which provoked the English ex- 

 peditions of Burton, and of Grant and Speke. 

 Dr. Albert Roscher planned the ascent of 



