264 Dynamic TJieory. 



times it becomes epidemic. This last, the epidemic disease, is a dangerous one. It if? 

 called also "black tongue," from the occasional appearance of the tongue. It appears 

 in isolated places at the same time, its miasm or infection doubtless being conveyed in 

 the air. It is not directly contagious, but rather infectious-miasmatic. 



Puerperal Fever arises from inflammation of the peritoneum, which 

 may attack a woman after the birtli of a child. The disease is infectious and has been 

 known to go through a whole hospital. It has often been observed that during epidem- 

 ics of Erysipelatous fever, Puerperal fever becomes much more prevalent ; and this has 

 led to the opinion that the erysipelatous infection is- able to set up the latter disease in 

 subjects who have been reduced in health and strength in certain organs. In other 

 words, the same "germ" or " ferment," if that is it, produces a different growth in dif- 

 ferent soils. 



Epidemic Bronchitis or Influenza. This disease is remarkably epi- 

 demical, being very extensively and rapidly diffused, and affecting a great number of 

 people at the same time. It affects the mucous membrane of the nasal passages, and of 

 the frontal sinus and other cavities connecting with them ; also the eustachian tube, the 

 conjunctiva,* and the tear ducts. These affections are accompanied by a fever. It is an 

 infectious disease communicated by means of the air which carries the miasm. An at- 

 tack of this disease lasts from three to six days and is rarely or never fatal unless accom- 

 panied by other diseases or the weakness of infancy or old age. It has been observed that 

 other diseases are more severe during the prevalence of influenza. 



Another epidemic disease is Ophthalmia. There are several varieties, 

 some of which are contagious. One of severity and danger is called Egyptian Ophthal- 

 mia. It consists of inflammation seated chiefly in the coats of the eyeball, and extends 

 in some degree to the eyelids. Another variety is a contagious granular conjunctivitis 

 or inflammation of the conjunctiva. This is also epidemic and contagious, and very com- 

 mon in some of the middle portions of the U. S. It may be " caught " by a person wiping 

 his eyes on a napkin or towel used by another who has sore eyes. 



Hydrophobia or Rabies. This disease arises in certain seasons and in 

 certain localities in dogs, foxes, wolves and cats " spontaneously." From them it is com- 

 municated to other animals including man, by blood inoculation. The virus of the disease 

 is contained exclusively in the fluids of the mouth ; viz., the saliva and mucous from the 

 throat and bronchi. There is no proof that other fluids of the body are competent to 

 communicate the disease. The inoculation takes place wiien by a bite the rabid animal 

 impregnates with its venomous saliva the nerve tissues of the victim. The disease does 

 not make its appearance till 30 or 40 days after the inoculation. A great many who are 

 bitten are not inoculated, and many who are inoculated do not take the disease. Some 

 say, that of those bitten not over one in twenty contracts the disease. In many cases the 

 saliva is wiped off the teeth by the clothing, &c. After the development of the disease 

 death usually follows within five days. The treatment is usually to cut out the muti- 

 lated part as quickly as possible and cauterize it. Animals who do not naturally bite, do 

 not communicate it, although they may have it. The seat of the disease is said by Dr. 

 Duboue, of Pau, to be in the brain and spinal marrow. The virus is not in the blood, but 

 is carried by the nerve and nervous fibers. This accounts for the delirum which attends 

 the disease and for its long period of incubation, which would probably be much shorter 

 if the inoculation were through the blood. 



Endemic Diseases. There is a class of diseases which depend on local 

 causes. In a certain place, or class of places, a person may be liable to take a certain 

 kind of disease which he would not be liable to in another locality, perhaps not far away. 

 These are called endemics. The causes are miasmatic emanations from the soil or 

 water, or from decaying organic matters in the locality producing the disease. Many of 

 such diseases after being started by local miasm, or contamination of some kind, are 

 thereafter infectious, as for example milk sickness. But in the same way is not almost 

 every disease infectious? We reject the flesh of all animals that have died a natural 

 death, regardless of the cause, and the butcher who kills a diseased animal and oilers to 

 sell it is regarded as a criminal. 



Among the endemic diseases, one of the most common and well known 

 is Fcrc.r and Ague, or chill-fever, or intermittent fever ; a disease which has been greatly 

 lessened in this country by the improvements incidental to the settlement and cultiva- 

 tion of the country; such as the drainage of marshes and swamps, the clearing away of 

 tliiekets or underbrush, and turning over the rich soil so as to allow the penetration of air 



* Conjunctiva is the mucous membrane of the eyelids and outside of the eyeball; it 

 connects the ball and the lids. 



