250 THE NEW ZEALAND FAMILY HERB DOCTOR. 
kidneys, and the bladder. The genital organs are not 
generally noticed in a sketch of this kind. 
The lungs and heart are contained in the chest or thorax. 
The capacity of the chest will vary according to the size of the 
individual. The lungs are the right andleft. Theright lung 
is the largest, having three lobes, while the left has but two. 
The substance of these is elastic and spongy. It is generally 
supposed that the power of contracting and expanding isin the 
lungs, but this is not the case; they aresimply passive. The 
diaphragm and the muscles of the thorax, by contracting press 
the breath out of them, and by relaxing allow the lungs 
to expand, and take in the air. The quick action of the 
above muscles enables us to cough and sneeze. It is 
interesting to know the great amount of air which passes in 
and out of the lungs in the course of the day. The quantity 
entering at each inspiration is about 40 inches per minute; $009 
per hour ; 48,000 in 24 hours. Between the lungs, and partly 
covered in front by the left one, lies the heart. It is enclosed 
in a sack called the pericardium. The heart is a muscular 
organ, with independent nervecentres. Its power and rapidity 
of contraction aremarvellous. Inthe normal condition of infant 
life it numbers about 150 beats per minute; in adults, 60. In 
24 hours it contracts and dilates over one hundred thousand 
times, "She working of this wonderful organ, propelling the 
current of life from before birth to death, shows the power of 
our Creator, and should satisfy and convince the fool, who says 
in his heart there isno God. The heart has four compartments, 
called auricles and ventricles. The former act as receivers of 
the blood as it comes from the veins. When the heart relaxes 
the valves of the left side open, and the venous blood flows 
from the auricle into the ventricle; it then contracts and sends 
the blood to the lungs. Being oxygenised, it is returned to 
the left auricle, then at dilation of left ventricle is received 
into it; and at contraction it is forced into the aorta, then to 
the arteries, then by the hair-like vessels to the most remote 
part of the system. The quantity of blood sent from the heart 
at each beat is about six ounces. This portion pushes the 
