
17 
a great deal of evidence, said the Doctor, in favour of this theory, 
for the disease known as “sleeping sickness” is due to the 
obstruction of the blood-vessels in the brain, caused by the 
presence of a worm. A third theory is that sleep is due to 
simple exhaustion of the nervous system ; and it was to this that 
Dr. Griffith evidently inclined as being the true cause of sleep. 
It was an old saying, he observed, that in order to sleep well both 
brain and body must be tired, and in this he felt there is con- 
siderable truth. The brain is the managing director of the whole 
body. ‘‘ How is it,” he asked, “ that a few minutes’ good sleep is 
worth more than hours of rest without sleep?” This showed that 
it is the brain which wants rest, which can only be obtained by 
sleep, for when awake the brain never rests. 
The lecturer now somewhat startled his hearers by observing 
that there is a part of the brain which never sleeps, although, 
after his explanation, it appeared to be the most natural thing in 
the world. The brain consists of two parts—the superliminal, or 
the higher brain, and the subliminal, or the lower brain. When 
we sleep it is only our higher, conscious self that sleeps ; it is only 
this conscious self that needs rest. It is the subliminal, or lower 
brain that never sleeps. To prove this Dr, Griffith quoted the 
case of our going to bed at night, making up our minds that we 
will rise at five o’clock next morning. We get up at five o’clock, 
but how do we do it? Have we thought about it all night? If so, 
our sleep has not done us much good. The truth is that our 
faithful other self, our subliminal brain that never sleeps, has 
come to our rescue and awakened us. It is this subliminal brain 
that is seen in such an active state in somnambulists. Sleep 
walkers rarely come to any harm, although they may walk in the 
most dangerous places ; their safety lies in the automatism of 
their moments. A particularly interesting part of the lecture 
dealt with dreams and trances, the power to see visions, and the 
faculty of holding spiritual communion with departed friends. 
Here, however, Dr. Griffith was rather stepping beyond the 
bounds of science, and invading the realm of psychical experience. 
It was doubtless new to many to learn that animals are dreamers. 
Dogs, storks, canaries, bullfinches, and eagles all dream, said the 
lecturer; but crocodiles are doubtful, he added, amid the 
laughter of the audience. A great deal in our dreams may have 
some physical reason. Thus when we dream of a mountain on 
our chests, that means, the Doctor humourously observed, that 
we have had lobster for supper! Again, when our feet become 
uncovered and get cold we dream that we are walking on ice ! 
Dr. Griffith closed his lecture with some admirably suggestive 
thoughts with regard to the psychical aspect of the question, and 
commended this branch of the subject to the special considera- 
tion of the Society. 
