12 
ANNIVERSARY ADDRESS. 
appropriately pass on to the opposing or rather balancing law 
regulating centrifugal force, which impels the earth to fly away 
from the sun; and so to the laws of the other macrocosmic forces, 
on the relations of which forces to one another the maintenance of 
the existing order of the universe would seem to depend. Not 
mere essays, however, but whole hooks would be necessary, even 
for the cursory treatment of these cosmical laws. For the purposes 
of this Address, however, what has already been stated should 
fully suffice in illustration of what may be termed the Macrocosmic 
Laws of God in Nature. 
We may now turn for a little while to what for purposes of 
description may be termed the Microcosmic Laws of God in Nature, 
that is, we turn from the contemplation of two or three of the laws 
of the macrocosm or universe to the contemplation of a few of the 
laws which are more personal to the microcosm or man. Afterwards 
we may again consider laws which have both macrocosmic and 
microcosmic interest, laws both celestial and terrestrial. 
Man lives under two chief conditions, he is either asleep or 
awake. Strictly speaking only a portion of our system can sleep. The 
heart and the lungs with their associated respiratory muscles never 
sleep—that is to say, not until they metaphorically sleep the long 
long sleep of what for them, as mere organs, is truly death. The 
heart is a perfectly-constructed pump, the action and work of which 
in pumping our life-blood are governed by the laws which govern 
the action and work of other pumps. The system of lungs and 
chest-muscles also may be regarded as a contraction-and-expansion 
apparatus or pump (in which diffusion does valve-work), an air- 
pump, the functions of which are controlled by the laws which 
control similar pumps. And these pumps, in our sleeping as in our 
waking hours, so gently force together the fluid in our veins and the 
all-purifying air, that by night we rest undisturbed and by day are 
alike unconscious both of the presence of these two engines and of 
the work they are ceaselessly performing. Study the mechanical 
laws which govern the action of the common water-pump and the 
less common but very simple air-pump, and you will understand the 
laws which govern the mechanical action of the heart and of the 
breathing-organs. But other laws are operating during respiration. 
How does the ever-inhaled air purify the ever-flowing blood ? Here 
the laws of combustion come into play. Study the laws which 
govern the matter and force of our factory furnaces or of our house¬ 
hold fires and flames, and you will understand the laws by virtue 
of which the air we breathe acts on the blood which flows through 
our veins. The food we eat is converted into blood under one series 
