Abstract of Paper 
By G. MUNRO smith, L.RC.P.Lond., M.P.C.S* 
HEN the hand is firmly pressed against the loft side of 
f f tlie chest, we can readily feel the rhythmical thumping 
sensation due to the movements of the heart beneath the ribs. 
These movements, which in thin people can be seen as well as 
felt, occur, in health, with perfect regularity, and are the out- 
ward sign of that enormous though unobtrusive wmrk on which 
our very existence depends. 
The heart is a strong, hollow, muscular cone, divided into 
four cavities, whi.h communicate with each other and with the 
whole circulatory apparatus of the body. Every time it 
beats/’ or contracts, it squeezes the blood into the arteries 
with sufiScient energy to make it travel at the rate of one foot 
per second. As the tubes into which it flows become ultimately 
extremely minute, there is great resistance to the onward 
stream, and a corresponding force is necessary in the central 
pump. For instance, each contraction squeezes out from nine 
to twelve ounces of blood, and does enough wmrk to lift a weight 
of three pounds to a height of three feet. As this occurs sixty 
times a minute at least, we can calculate that in 24 hours this 
small engine does work equivalent to raising 124 tons to a 
height of 1S4 feet. The heart of old Sir Moses Montefiori, 
whose hundredth birthday w^as celebrated a few months ago, 
must have beaten more than 5000 niillions of times, and 
manifested enough energy to raise five millions of tone to a 
