428 



THE POPULAR SCIENCE MONTHLY 



accordingly considered the star to be a fifth 

 satellite of Jupiter. The statements con- 

 tained in his letter agree sufficiently with 

 the assumption that the star was or is a 

 variable fixed star, and the diagrams and 

 descriptions indicate that the conjunction of 

 Jupiter and of the star occurred on April 

 7th. By means of the geocentric place of 

 Jupiter computed for the date, Winnecke 

 has been enabled to identify the observed 

 star with Lalande's 18,886, a star of the 

 eighth or the seventh to eighth magnitude, 

 which, during the last half century, seems 

 to have varied little in brightness. Vari- 

 able stars, in the sense of the term as now 

 used, were unknown in Schemer's time, and 

 his description of the rapid decrease of the 

 star's light carries with it some proof of its 

 truthfulness. The spectroscopic observa- 

 tion of this star, with sufficiently powerful 

 instruments, would be very desirable. Its 

 place for 1855, date of the Bonner Durch- 

 musterung, is right ascension 9h* 29m. 

 212s., and declination +15 52-1'. 



Identity of Hvat and Light. In a re- 

 cent lecture, Mr. W. H. Preece, the English 

 electrician, made the following interesting 

 remarks on heat and light: "These two," 

 he said, "are identical in character, though 

 different in degree ; and whenever solid mat- 

 ter has imparted to it motion of a very high 

 intensity in other words, when solid mat- 

 ter is raised to a very high temperature it 

 becomes luminous. The amount of light is 

 dependent on the height of this tempera- 

 ture ; and it is a very remarkable fact that 

 all solid bodies become self-luminous at the 

 same temperature. This was determined by 

 Daniell to be 980, by Wedgwood 947, by 

 Draper 971 ; so that we may approximate- 

 ly assume the temperature at which bodies 

 begin to show a dull light to be 1,000. 

 The intensity of light, however, increases in 

 a greater ratio than the temperature. For 

 instance, platinum at 2,600 emits 40 times 

 more light than at 1,900. Bodies when 

 raised to incandescence pass through all 

 stages of the spectrum ; as the temperature 

 increases, so does the refrangibility of the 

 rays of light. Thus, where a body is at a 

 temperature of 250, it may be called warm ; 

 at 500, hot. At 1,000, we have the red 

 rays ; at 1,200, the orange rays ; at 1,300, 



the yellow rays ; at 1,500, the blue rays 5 

 at 1,700, the indigo rays ; and at 2,000, 

 the violet rays. So that any body raised 

 to a temperature above 2,000 will emit 

 all the rays of the sun. Inversely, the spec- 

 troscope may thus be enabled to tell us the 

 temperature of the different lights, and it is 

 perhaps because some lights do not exceed 

 1,300 that we have all the rays beyond 

 the yellow." 



A Dorse with a Load in his Stomach. 



Dr. Albin Kohn recites in " Die Natur " the 

 particulars of the sudden death of a horse, 

 caused by the presence of a stony concre- 

 tion in the animal's stomach. The horse 

 was to all appearance perfectly sound and 

 well one morning when carrying his master 

 about his estate, when suddenly he fell dead. 

 A veterinarian opened the carcass to ascer- 

 tain the cause, and found in the abdominal 

 cavity a stone of about eight pounds' weight, 

 and in the wall of the stomach a hole of cor- 

 responding size. The stone was submitted 

 to Dr. Peters, of Posen, for analysis, who first 

 cut it into halves. Each half of the rather 

 round stone called by Dr. Peters " magen- 

 stein," i. e., stomach-stone looked very 

 much like a Chester cheese. The diameter 

 of the cut surface was from 15 to 17i centi- 

 metres, and concentric rings are visible in 

 it. At the center its texture is radiate. Dr. 

 Peters supposes the animal at some time 

 swallowed a fragment of millstone, and that 

 around this nucleus numerous layers were 

 afterward deposited. Externally the stone 

 is smooth, rather hard, and of a grayish- 

 yellow color; its composition is: ammonio- 

 magnesic phosphate 87- per cent., organic 

 matter 6^, water 1, silicic acid 1; other 

 salts per cent. 



"Jnniping Frenchmen." It is a very 

 instructive narrative which Dr. G. M. Beard 

 publishes of the doings of the "Jumpers" 

 of the woods of Maine and Canada. These 

 jumpers are mostly half-breed French-Cana- 

 dian lumberers who have acquired the per- 

 manent habit, which they can not control, 

 of jumping or striking out with their hands, 

 when commanded to do so by any one who 

 chances to lie near. The habit appears to 

 have been acquired, in the first instance, by 

 tickling one another in the winter camps 



