212 PHARMACEUTICAL BACTERIOLOGY. 



place, due to carelessness on the part of the patient, and not due to the 

 virus used, but even this is an extremely rare occurrence. Since the incu- 

 bation period of small-pox is about twelve days and that of vaccinia (cow- 

 pox) is only five or six days, it is evident that the vaccination will establish 

 immimity even in those who were actually exposed, provided vaccination 

 is done within a few days aften exposure. 



Primitive (savage) races are very susceptible to small-pox, with a very 

 high mortality rate. This is in part due to the total ignorance of sanitary 

 measures, resulting in the more ready spread of the contagion. Entire 

 savage tribes have been exterminated by this disease. Negroes are far 

 more susceptible than Caucasians. Indians have spread the infection in 

 blankets after having been exposed. 



E. Malaria. — ^This familiar disease, commonly known as ague, the 

 shakes, chills and fever, and intermittent fever, prevails in many areas in 

 the United States and is limited to swampy wet countries. It gradually 

 disappears with the tilling and the draining of soil which remove the breed- 

 ing places of the only carriers of the disease, namely the mosquitos (An- 

 opheles). The primary causes is the Plasmodium malaria (Hamatozoa 

 malaria) which is introduced into the circulation by the sting of the mos- 

 quito. 



The prophylactic measures consist in the destruction of the mosquitos 

 in rooms. To this end burn two pounds of Pyrethrum to every thousand 

 cubic feet of space. Sulphur one pound per thousand cubic feet may be 

 used though it offers no advantage over the Pyrethrum and has the dis- 

 advantage of corroding metal and fading colored fabrics. Also destroy the 

 breeding places of the mosquito and keep mosquitos out of houses by means 

 of screens and netting. Protect the person against mosquito stings when 

 travelling in countries known to be infested by the Anopheles group of 

 mosquito. Also take qiiinine as a prophylactic (3 to 5 grains twice daily), 

 and as a cure. Quinine is, however, more satisfactory as a preventive than 

 as a cure. The Plasmodium is knowii to be very susceptible to the action 

 of quinine. 



F. Diphtheria. — This dread disease is both infectious and contagious. 

 The primary cause is the Bacillus diphtheria also known as the Klebs- 

 LoeflBer bacillus. The chief predisposing causes are exposure to wet and 

 cold. The disease may be localized in the larynx (membranous croup), in 

 the pharynx, in the nares, on any of the mucous membranes, and in cuts 

 and wounds. Animals such as cats may carry the infection. It is also 

 stated that the bacillus is apt to occur in certain soils and in stable manure. 

 The sick must be isolated and all discharges from nose, mouth and throat- 

 as well as the bed linen, etc. , must be sterilized and disinfected. Upon recovery 

 the sick-room must be thoroughly fumigated by means of formaldehyde. 



