PHYSIOLOGY AND ANATOMY. 27 
and smaller in size than the arteries, and have valves in them 
somewhat like those in the arteries, and brings the blood to 
the heart. If we accidentally cut a vein there is not much 
“danger, but if an artery be severed and the ends are not im- 
mediately tied, death will be the result. By feeling the pulse — 
we find how rapidly the blood passes or circulates, and as the 
artery at the wrist is nearer the surface than any other, it can 
be — on with more certainty. : 
By palpitation of the heart, we mean that there is some 
- obstruction in the way, which makes the circulation irregu- 
lar. This palpitation is considered very dangerous, as our 
lives depend on the regular circulation of the blood. We 
ought not to breathe the same air the second time, for if ‘we 
do, it will not then contain sufficient oxygen to produce that — 
change necessary for good blood. In ree to have as pure 
air as possible, we should ventilate our rooms, especially those 
in which we sleep. When the blood is taken from the body, 
and exposed to the air, it becomes thick, or coagulates ; little 
yellowish particles of fluid arise, which are called the serum ; 
a thick substance i is left, which, when washed, loses its rat 
earanee, and becomes white ; this is called the fibrine of 
the blood. si 
. Consumption means that the lungs, liver, muscles, or other 
organs of the body, is consumed, or incapable of, in- 
haling a sufficient quantity of air to support life. This dis- 
ease is produced by exposure to the cold, wearing thin shoes 
in cold and damp weather, and by drawing the clothes so 
tightly around the ribs that they erowd in and destroy the- 
lungs. This might be prevented in a variety of cases ae 
proper care and attention. 
