SCIENCE 



[Vol. XVIU. No. 445 



tbat the total damage done by them is too insignificant to justify 

 their persecution in well-wooded regions. 



London Iron says: "A novelty in boat building is the tiny 



steamer just completed for the Frankfort Electrical Exhibition by 

 Messrs. Escher, Wyss, & Co. of Zurich, and which made a suc- 

 cessful trial trip on the Limmat the other day. It is constructed 

 entirely of aluminum, even to the engines and screw propeller, 

 and is the first vessel that has been built of the light, ductile, sil- 

 ver-white 'metal of the future.' The lilliputian bark is twenty 

 feet long and five feet wide, and is driven by a two horse power 

 naphtha motor. As this compact style of engine, when, as is 

 usually the case, it is wrought out of iron, is abeady considered 

 one of the lightest on the market, the further advantage gained 

 in this respect when the motor is constructed of aluminum is ob- 

 vious." 



— That severe mental distress or fright sometimes produces 

 physical disease, and occasionally even death, is an admitted fact, 

 according to the Lancet, although the way in which it acts has 

 hitherto been but little studied. In order in some measure, to sup- 

 ply the deficiency in our knowledge regarding this mattet, Dr. G. 

 Bassi has recently made a number of observations on animals 

 which apparently died in consequence of capture. Birds, moles, 

 and a dog which had succumbed to conditions believed by Dr. 

 Bassi to resemble those known among human beings as acute 

 nostalgia and "a broken heart," were examined post mortem. 

 Generally there was hyperaemia, sometimes associated with capil- 

 lary hemorrhages of the abdominal organs, more especially of the 

 liver, also fatty and granular degeneration of their elements, and 

 sometimes bile was found in the stomach with or without a 

 catarrhal condition. The clinical symptoms were at first those of 

 excitement, especially in the birds, these being followed by de- 

 pression and persistent anorexia. The theory suggested by Dr. 

 Bassi is that the nervous disturbance interferes with the due nu- 

 trition of the tissues in such a way as to give rise to the formation 

 of toxic substances, — probably ptomaines, — which then set up 

 acute degeneration of the parenchymatous elements similar to that 

 which occurs in consequence of the action of certain poisonous 

 substances, such as phosphorus, or to that met with in some in- 

 fectious diseases. In support of this view, he points out that 

 Schule has found parenchymatous degeneration in persons dead 

 from acute delirium, and that Zenker found hemorrhages in the 

 pancreas in persons who had died suddenly. He refers also to 

 some well-known facts concerning negroes in a state of slavery, 

 and to the occasional occurrence of jaundice after fright. He 

 hopes that these hints may induce medical oflScers of prisons and 

 others to study both clinically and anatomically this by no means 

 uninteresting or unimportant subject. 



— Additional experiments and observations upon ammonite 

 seem to confirm the first opinions regarding its safely and its 

 power. Direct application of heat or concussion fail to explode it. 

 Atmospheric changes exert no influence upon it whatever. It has 

 been tried in a large number of the most dangerous coal mines in 

 England without igniting the gases which were known to be present 

 at the time. A mixture of coal-gas and coal-dust was not exploded 

 by it, even when no more than two inches of tamping was used. 

 The safety tests have been so thorough and satisfactory that the 

 railroads of the United Kingdom accept ammonite as freight with- 

 out the usual restrictions placed upon explosives, ami it even meets 

 the requirements of Sir George Elliot for perfect security, which 

 is saying a great deal. According to the Railroad Gazette, am- 

 monite consists of an intimate mixture of 81| per cent of ammo- 

 nium nitrate and 18+ per cent of mono-nitro-naphthalene. The 

 manufacture is extremely simple and practically unattended with 

 danger. Being free from chlorates it is not liable to decomposi- 

 tion or spontaneous combustion. Having no picric acid or chlori 

 nated derivatives of hj'dro-carbons in its constitution it yields no 

 injurious or corrosive fumes among its products of combustion. 

 [t is put up for use in lead-foil cartridges and exploded with a 

 detonator. Tests made in England on July 9 showed that it pos 

 sesses great strength, a projectile of 29 pounds weight being thrown 

 from a mortar elevated forty-five degrees to a distance of 830 feet 

 from the muzzle by a five-gram charge, as against 289 feet by a 



similar charge of No 1 dynamite, and 136 feet by an equal weight 

 of gunpowder. Notwithstanding this, ammonite has as yet only 

 been proved of value in comparatively soft material. Experiments 

 are in progress, however, to secure if possible a high efficiency 

 with this explosive in hard rock work. While the security claimed 

 for ammonite is highly encouraging it should be remembered that 

 it is comaionly "the unexpected that happens." It would seem 

 that ammonite possessed a special virtue in the absolute safety of 

 its separate ingredients, and in the great ease of its manufacture, 

 which would enable it to be made upon the spot where it was 

 needed, by any one having even a meagre knowledge of chemistry, 

 and with a very inexpensive plant. 



— The Supreme Council of Hygiene of Austria has been engaged in 

 discussing the advantages of erect as compared with slanting writ- 

 ing, and the official report of Drs. von Eeuss and Lorenz points 

 strongly in favor of the former. According to the London Educa- 

 tional Times, they point out that the direction of the written charac- 

 ters has a marked influence on the position of the body. In "straight" 

 writing the scholar faces his work, and is spared the twist of the 

 body and neck which is always observable in those who write 

 slantwise, and one common cause of spinal curvatui-e is thus ob- 

 viated. The erect method is, therefore, expressly recommended 

 for use in schools in preference to the ordinary sloping lines. 



— M. Constantin Miculesco has communicated to the Paris 

 Academie des Sciences a note on a new determination of the me- 

 chanical equivalent of heat. According to Engineering, the 

 method used was in principle the same as that of Joule, viz., the 

 production of heat in a calorimeter by means of friction. In 

 Joule's experiments, however, the total work done was small, and 

 hence a long time was required to obtain a sensible heating of the 

 calorimeter, and various difficult corrections had to be made. 

 To avoid this, M. Miculesco made use of a fairly powerful electro- 

 motor to supply the work which was to be turned into heat. 

 The apparatus consisted of a one horse-power Gramme electro- 

 motor, carried on a frame suspended on knife edges, the shaft of 

 the motor being central with the line of these supports. A calo- 

 rimeter consisting of two concentric cylinders was mounted on a 

 separate frame, so that the axes of the cylinders coincided with 

 the centre line of the motor shaft. This shaft was coupled, by a 

 flexible connection, to one carrying paddles, which it caused to 

 rotate in the water in the cylinder. Under these circumstances 

 the frame carrying the motor tended to swing on its knife-edges 

 so as to balance the torque on the motor shaft, and by correcting 

 this tendency by carefully adding weights, this torque could be 

 measured with great accuracy. The result obtained was J=777. 7 

 foot pounds. 



— The United States Coast and Geodetic Survey Office at 

 Washington has received a report from Assistant J. E. McGrath 

 of that service, dated June 20, 1891. Camp Davidson, Upper Yu- 

 kon River, near eastern boundary of Alaska, in whicli he states 

 that the health of the party has been excellent, and the work a,t 

 that station is practically completed; and that as soon as the 

 necessary solar observations for rating the chronometer could be 

 obtained, they would leave for St. Michael's. The trip will be 

 made in open boats, as certain magnetic observations were to be 

 made at Fort Yukon, obliging the party to stop there. Jlr. Mc- 

 Grath expects to reach St. Michael's by Aug. 25, and in time to 

 come south on the revenue cutter " Bear." In his report Mr. Mc- 

 Grath states that the astronomical observations have been very 

 much delayed by cloudiness and rain. Meteorological observa- 

 tions have been continuously made three times a day. The aver- 

 age monthly temperature since December shows an increase of a 

 few degrees over the same months of the preceding year. The 

 lowest minimum temperature noted was on Jan. 16, on which 

 date the lowest temperature read was —60.5° F. The Yukon 

 River opened nine days later this year than in 1890. Mr. Mc- 

 Grath sjjeaks in the highest terms of the diligent and faithful 

 conduct of all the members of his party, mentioning by name his 

 assistants Mr. Da^is and Dr. Kingsbury. The latter gentleman 

 had at the date of the report left camp for home, carrying with 

 him the duplicate records of the party, it being deemed safer to 

 have them sent ahead of the originals, to avoid possible loss of 



