460 On Electricity and its Present Applications. [August, 
much less to describe them. The analogy, nay the identity, 
of Electron and heat can be experimentally and otherwise 
shown in a variety of ways ; but there is not time t0 
more than allude to this interesting department of the cor- 
relation and mutual convertibility of physical forces. 
Let us for a moment change the metaphor so long kept 
up and, by using the magician’s power, transform our Genie 
into a wild steed of the Desert, careering at his own way- 
ward will through the prairie and the forest,— -dangerous 
and difficult to come to close quarters with,— admired for his 
beauty, power, and speed, yet feared and avoided because so 
untameable and intractable ; but when once a material bridle 
is imposed upon him his speed is greatly subdued, and 
becomes the means of carrying man along with him, and ot 
revealing to him all the beauty, grandeur, and wonders ot 
the world. When still further subdued, harnessed, and 
accoutred, he not only diffuses happiness and life all around 
him, but can be made to perform a variety of most useiul 
and admirable work, far surpassing in quality and value that 
of any other creature within the power of man. 
Electricity, Light, and Heat may be said to be a unity in 
trinity, recondite and mysterious to us, but not altogether 
incomprehensible,— a type or analogy, may we not say, ot 
that greater and still more incomprehensible mystery, the 
dogma of the Divine essence, which forms an important part 
of the Christian creed, and which it may well encourage and 
justify us in believing, even although its full comprehension 
may be beyond our imperfect powers. 
Whatever may be thought of the marvellous and benefi- 
cent powers of this great Genie, as I have attempted to 
describe them, in reference to the Cosmos, there is a depart- 
ment of the work assigned him by his Creator which is to us 
(I mean to medical men) as important, if not even moie 
interesting and wonderful. I allude to the services he pci- 
form s in regard to the Microcosmos, and in the development 
and the vital aCtion of all living creatures, bearing, as these 
of course do, upon the physiological and medical aspects of 
Anthropology. On some of the mysteries of these subjects 
it is probable that there will fall in time a share of the light 
which his scientific cultivation is now throwing on other 
subjects of human interest and utility. But into this de- 
partment I shall not attempt at present to entei. 
The functions of Electron— lying, as many of them do, 
in the border-land between spirit and matter, have given 
occasion of late to a contention regarding the respective 
claims of superiority due to spirit and matter, in carrying 
