Lecture

 1 I  |      illustration I produced an effect than which nothing could
 2 I  |       same time [exhibiting the effect]. I dare say, if I were
 3 II |        of Nature, and what they effect, unless we now and then
 4 II |        was held. I can show the effect better in this bottle of
 5 II |      will show a very different effect. It no longer goes to that
 6 II |        then, internally, has no effect upon light. [The glass was
 7 II |       you that the glass has no effect upon it in its ordinary
 8 II |         will see what a curious effect that has. [Upon the screen
 9 II | structure and produce a similar effect. Here is a piece of common
10 III|   excellent illustration of the effect of a power of nature which
11 III|        a comparison between the effect produced by air and oxygen.
12 III|       wonderfully different the effect is in the jar, because there
13 V  |        of the needle, it has no effect upon it, either of attraction