58 Proceedings of the Royal Society 
3. Topical application destroys the contractility of striped and 
of unstriped muscular fibre. The heart’s action is stopped by 
repeated application to the pericardium or to its external surface. 
If a sufficient quantity be injected into one of its chambers, para- 
lysis nearly immediately follows. 
4. The effects of the application of Calabar bean to the eyeball 
are a somewhat painful sensation of tension in the ciliary region, 
contraction of the pupil, with immobility in extreme contraction, 
myopia and astigmatism, congestion of the conjunctival vessels, and 
twitches of the orbicularis palpebrarum muscle. 
3. Od some Phenomena of Indistinct Vision. By Edward 
Sang, Esq. 
If an exceedingly small luminous object be placed in front of 
the eye, but out of the range of distinct vision, it appears to be a 
roundish bright disc traversed by various markings, and most of 
these markings are found to be permanent for the same eye, but 
different for the two eyes. The subject of the present paper is a 
modification of this appearance. 
Instead of a luminous point let us take a very narrow luminous 
line, such as a small slit in the window-shutter, or the reflection of 
the light of a fire from a polished metallic rod, and let us put this 
out of focus by means of a pair of convex spectacles. On regard- 
ing the luminous line, without any attempt to adjust the eye to 
distinct vision, we perceive a long luminous band, the breadth of 
which varies with the distance of the line. When the luminous 
line is brought into focus, the apparent breadth becomes zero ; it 
increases as the line is moved beyond or within the distance for 
distinct vision. 
If, having removed the shining line to a considerable distance, 
so as to obtain a pretty broad band, we take a thin ring, such as 
that used for keys, in the hand, and pass it close to the eye so as 
to intercept part of the light, we shall perceive that the bright 
band is traversed for its whole length by a dark line, and that this 
line moves across it in the direction of the motion of the ring. 
On removing the ring to a little distance, the black line produced 
by it is seen to be curved in the same direction with the curvature 
