OF ARTS AND SCIENCES. 373 



that shall be consistent with the law of strength for small as well as 

 for large columns. 



Whereupon a committee, consisting of Daniel Treadwell 

 of Cambridge, J. B. Francis of Lowell, and J. B. Henck of 

 Boston, was appointed to examine and report upon the whole 

 subject. 



Professor G. P. Bond communicated the results of a series 

 of photographic experiments, executed at his request by Mr. 

 Whipple, upon the light of the Sun and Moon, compared 

 with that of the planet Jupiter. 



The results tend to support the suggestion that the latter is a self- 

 luminous body. Several analogies were pointed out. The physical 

 constitution of the atmospheres of the Sun and Jupiter, the periods of 

 the solar spots, and the phenomena attending the transits of the satel- 

 lites of Jupiter, were referred to in the same connection. 



Professor Bond stated that a phosphorescent condition of the atmos- 

 pheres of the larger planets might be anticipated as a consequence of 

 Vaughan's theory of the source of solar heat and light, and that this 

 consideratij^i had first suggested the experiments in question. His 

 object, however, was not* at all to advocate the theory, but rather to 

 present a variety of facts, all tending to show a remarkable analogy 

 between the Sun and the largest planet of the system. 



Dr. Holmes proposed the term Reflex Vision to characterize 

 the visual acts illustrated by the following experiments : — 



1. Close one eye, leaving the other open. Hold a finger between 

 the open eye and some small object, so as to conceal this object. Open 

 the other eye, and the object will be seen as if through the finger. 



2. Place the hand edgewise between the eyes, so that the eye last 

 opened cannot see the finger. The object will still be seen as if 

 through the finger. 



3. Place a wafer on the back of a paper stereograph, so that it can 

 be seen in the instrument by one eye only ; for instance, the left. An 

 image of the wafer will be seen in the right side of the stereoscope, 

 which cannot always be distinguished from the wafer itself, except by 

 trying it with the finger, or in some similar way. The left image may 

 be called direct, the right, secondary. 



