134 Transactions of the American Institute. 



burning in the flame, wliich give lis this characteristic light as well 

 as heat. Below we have a bluish tinge and above we have the red, 

 and intermediate the yellow ; and thus we have the same series of 

 rays that we And in the solar spectrum. This has been taken as the 

 type of all forms of light. Suppose that we liad only the ordinary 

 street gas, and some one should come forward and claim that he could 

 condense the gas into a solid form, cleanly, white, compact, which 

 you could even carry in your pocket or in a trunk without injury, 

 and yet you could apply to it a match and evolve from it gas, and 

 could burn it so as to furnish an ordinary light, what a triumph the 

 candle would be over modern chemists. The flame of the candle 

 well illustrates the physiological phenomena constantly occurring in 

 our own bodies, AVe live in oxvsren o-ns, and are converted into the 

 carbonic acid and vapor of M'ater into which this candle passes. Sad 

 to say, while we are bright and luminous without, we are too often 

 dark within. 



From the candle we may pass to the variety of light which we may 

 obtain from diflerent liquids of the earth. You all know that we 

 may obtain oils from the animal world, and from the plants ; and 

 from the animals that inhabit the sea as well as those that dwell on 

 the surface of the earth. But let us remember that all of these sub- 

 stances have derived their life from the sunbeam ; and hence the light 

 we get has been derived from that source. Let us go even to that oil 

 which bubbles up so generously in our own soil, and has been found 

 in other lands, the rock oil, or petroleum; so that we not only have 

 a land " flowing M'ith milk and honey,'- but we have the richness and 

 fatness of the earth pouring forth, and which has been such a source 

 of pleasure and proflt in our own time. These oils are derived from 

 that extraordinary source, the coal. Familiar as the facts are to all 

 of us, that the coal is the stored-up residue of the ancient life that 

 once decorated our planet, we may not always remember how entirely 

 different that was from the vegetable life we now And about us. The 

 earth was not then a planet fitted for us to live upon. There was 

 not a plant fitted for the humblest of our animals. There were none 

 of the fruit-bearing trees ; none of the classes which give to us the 

 peach, the apple, the glowing pomegranate, the gorgeous orange, and 

 the like ; not one of the cereal grains, the wheat, the rye, the oats, 

 the barley ; none of the sweet-smelling herbs ; none of the flowering 

 plants; at the same time there was none of the varied and 

 beauteous forms of insect life which lived upon the flower ; but 



