458 TRANSACTIONS OP THE AMERICAN INSTITUTE. 



upper teeth. ^ In this case the sound expresses the curious perraeatingl 

 qualities of the fluid. The name eeth, or, if preferable, eeth, is short and 

 peculiar, and in every way admirably adapted to distinguish this most 

 mysterious kind of matter.* We are aided in our conceptions with regard 

 to the motions of seth by a comparison with motions of air. When seth 

 moves in currents it resembles ivind; when it moves in waves it resembles 

 sound. It should be remembered, however, that air waves producing 

 sound, move to and from a center of motion, alternately expanding and 

 condensing the air in the same sight line, while eeth waves move trans- 

 versely to line of the ray. The forces manifested through the wave motion 

 are three, and are distinguished thus: 1st. The force of heat b}'' the name 

 setheat. 2d. That of light, by ^thight. 3d. That of actinism, by asthac. 

 It will be noticed that the effects of wave motion are designated by words 

 formed by placing another syllable after the word seth. All other manifes- 

 tations of change or force in teth are designated by prefixes. Thus, the 

 force passing through eeth in currents, known as electricity, is designated 

 by curiBth. According to the theory of Franklin, the positive and negative 

 condition of electricity is produced by an excess or deficiency of the fluid; 

 condensed teth is therefore designated as condieth, and rarified eeth as 

 raraith. That force of jeth, known as magnetism, will properly be called 

 magnseth. 



To return again to the phenomena of seth in undulation, it is often 

 essential to speak of the calorific, colorific and chemical effects as exhibited 

 . strictly within the luminous spectrum; these are designated severally as 

 calsethight, colcethight and chemEethight. That anomaly in the action of 

 light which is the force of that portion of the sheaf of waves moving in the 

 same plane, called polarization, is designated as poleethight. A similar 

 effect of the waves of invisible rays producing heat is called polcetheat. 



It is evident that any newly discovered action of reth can easily be dis- 

 tinguished by compound words similar to those already given. 



Mr. Enos Stevens spoke of the changes of temperature caused by atmos- 

 pheric pressure; the attraction which produces tidal influences affects the 

 atmosphere in a similar way; it is alternately contracted and expanded, 

 thereby giving rise to heat and cold. He believed many of our sudden 

 changes of temperature had this origin rather than that which arises from 

 the direct action of the sun in rarifying the air. It is from the atmospheric 

 coating of the earth that much heat is given to and taken from the animals 

 upon it. According to this supposition, that the heat of the sun depends 

 on the thickness of this coating, we may coiiceive how planets receiving 

 different amounts of heat from the sun may have nearly an equal tempera- 

 ture on their solid surfaces. If atmospheric pressure modifies temperature, 

 and that pressure is affected by the changes in the attractive power of 

 celestial bodies, it follows that what may be called the tidal element must 

 enter into many of our meteorological calculations. 



* As this article goes to press, we add that Prof. Tyndall, of the Royal Institution of Great 

 Britain, in his admirable lectures just published, says : " If we could change either the name 

 given to the interstellar medium, or that given to certain volatile liquids by chemists, it 

 would be an advantage. It is difficult to avoid confusion in the use of the same name for 

 objects so utterly diverse." 



