194 



SCIENCE. 



[N. S. Vol. XI. No. 266. 



HEARING IN ANTS. 



In a recent number of Science (Nov. 24, 

 1899), LeRoy D. Weld describes some experi- 

 ments iipou a number of species of ants, dem- 

 onstrating a sense of hearing. It may be of 

 interest to lecord that in 1895 one of my stu- 

 dent^i. Miss E. A. Wagner, who was keeping 

 several species of ants under observation, found 

 one species (not determined) of small black ant 

 which gave unmistakable evidence of hearing. 

 Miss Wagner's work was never completed, so 

 that I can only give, from memory, an inade- 

 quate account of her results. 



To most sounds this species, like the others 

 studied, was apparently indifferent, and, so 

 far as we could judge, insensible, but to a 

 note of a certain pitch, whether sounded by a 

 violin or by a whistle, the whole colony would 

 react most vigorously, rushing about frantically, 

 tumbling against one another, many of them 

 falling into the water moat surrounding the 

 nest, a thing they never did when undisturbed 

 The appearance was that of extreme agitation. 

 This response was obtained only to sounds of a 

 certain pitch. On first sounding the note the 

 ants which might be resting quietly in a com- 

 pact group in the nest (asleep ?) would appar- 

 ently be startled to attention, standing tense 

 with erect antennse. A few of the outermost 

 ants in the group would usually move about a 

 little, but if the sound was not repeated they 

 might return and all the individuals again be- 

 come quiet. If the sound were repeated sev- 

 eral times at intervals the agitation (?) would 

 steadily increase until all the ants seemed 

 fairly frantic, behaving in a way never observed 

 under other circumstances. The reaction was 

 equally decided whether the note was sounded 

 near the nest or fifteen feet away at the oppo- 

 site side of the room with the back turned to 

 the nest. In only one species was any response 

 observed, and in this species the response was 

 only to a note of a certain pitch. 



It is difiBcult to explain the violent reaction 

 to only this particular note. What connec- 

 tion, if any, it may have with any features of 

 the normal environment of these ants, I cannot 



suggest. 



Maynabd M. Metcalf. 

 Thb Womans College of Baltiuoee. 



NOTES ON INORGANIC CHEMISTRY. 



After having been practically stationary for 

 a number of years, the manufacture of sulfuric 

 acid, which is the greatest of the chemical 

 industries, has lately begun to make new and 

 unforeseen advances. The first of these is the 

 use of cast-iron vessels for concentration and is 

 described by E. Hartmann in the Chemiker 

 Zeitung. The great rise in the price of platinum 

 has emphasized the necessity of some more 

 economical material for concentration vessels, 

 and it is found that, unless it is desired to have 

 an acid absolutely free from iron, vessels of cast- 

 iron can be used. The iron should be as free 

 as possible from all impurities and as hard as 

 possible. The acid is concentrated in lead 

 pans to 61° B, then run into a small cast-iron 

 vessel in which it reaches 63.5°-64° B, at a 

 temperature of 180°. Finally it is run into two 

 concentrating dishes in cascade arrangement, 

 where a strength of 9T fc to 98 /o is obtained. 

 The small vessel lasts three to four months and 

 the concentrators from six months to over a 

 year. The loss on wear of apparatus is how- 

 ever no greater than with platinum, and the 

 first cost is insignificant in comparison. 



The second advance iu sulfuric acid manu- 

 facture is nothing less than a complete revolu- 

 tion, and is described by Lunge in the Journal 

 of the Society of Chemical Industry. It is the 

 complete abolition of the lead chamber and 

 towers, even of the use of nitrous fumes as 

 oxygen carriers, and the use of the so-called 

 catalytic power of platinum and other sub- 

 stances to occasion the union of sulfur dioxid 

 and oxygen. In other words it is the utiliza- 

 tion of an idea which has long been considered 

 available for the preparation of sulfur trioxid 

 and Nordhausen fuming acid. The Badische 

 Anilin and Soda Fabrik has perfected this 

 invention and is manufacturing its acid practic- 

 ally by this process and other firms are begin- 

 ning to follow in its steps. Among the catalytic 

 agents which have been used are pyrites, cinders. 

 The principle feature of the Badische invention 

 is the discovery that to obtain good results it 

 is necessary to get rid of the heat of the reaction. 

 With this it is possible to attain 98 per cent, 

 of efiiciency. The process is of course of great- 



