126 ANATOMY AND PHYSIOLOGY. 



chickens in a dark and damp cellar, and upon a scanty diet, they 

 are rapidly carried off by this affection. Though the lungs are th 

 parts most usually affected by this disease, it is a mistake to su 

 pose that it is a merely local complaint. Very commonly, th 

 cheesy matter is found, at the same time, in the liver, mesentery 

 and many other parts ; and there can be little doubt that the essen- 

 tial cause of the whole is a particular form of constitution, either 

 inherent from parents, or brought on by irregular habits, want of 

 fresh air and exercise, or other diseases and circumstances that 

 enfeeble the body. Where the predisposition to this disease is 

 very great, we see whole families cut off by it; but when the pre- 

 disposition is less, we often notice only those affected that follow 

 occupations, or have contracted habits, that impair their health.* 

 The woeful system of quackery pursued by our popular doctors, con- 

 sisting of bleeding and mercury, is another fruitful source of pulmo- 

 nary diseases. 



The mechanism of respiration may be beautifully seen in the 

 rabbit. After skinning, &c., open the belly, take out the intes- 

 tines, liver, &c., and cut through the spine high up with a strong 

 knife. The diaphragm, separating the belly from the chest.J 

 then be seen. To show the parts contained in the chest, next take 

 away the fore-legs, and cautiously detach the ribs from the breast 

 bone, on each side, except at the top and bottom, breaking or cut- 



* We have said that consumption is a hereditary disease, or arises from a peculiar 

 constitution transmitted from parents to children. This is what is called the scrofulous 

 constitution, which can often be detected by a practised observer, but of which it is not 

 easy to give any definition, except that the formation of tubercular (cheesy) matter in 

 any part always denotes it. When much developed, and when it affects the glands of 

 the neck, it is vulgarly termed " king's evil." Constitutions are variously tainted with 

 it, however, from a very slight to a very high degree ; and it may easily be conceived 

 how generally the taint is diffused, when we have stated that one in every four or five 

 dies in this country from one of its forms. There are many other diseases, the tendency 

 to which is derived from parents, such as asthma, insanity, gout, &c. ; and there can be 

 little doubt that this class of diseases constitutes the great bar to the physical improve- 

 ment of the human stock. Until correct views on this subject become more general, 

 little hope of improvement can be entertained. At present, persons in every rank make 

 eager inquiries as to the worldly condition, &c., of those who are likely to form their 

 partners for life; but how seldom does it happen that the tendency to even serious 

 hereditary disease forms a bar to their union, or that persons even take the least pains 

 to satisfy themselves where such exists ! The great part of mankind neglect far too 

 much the fact that they are animals, and that they are therefore subject to those general 

 laws which regulate the transmission of peculiarities or diseases to their children. 

 Hence, from this serious error, they fail to take the precautions which are necessary to 

 secure an approach towards physical perfection in their own progeny, the neglect of 

 which they would be ashamed of, even in regard to their dogs and their horses. 



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