9 



pollution of the atmosphere and assailed man by way of respiration. 

 This doctrine was accepted by the pupils of Galen. In the commen- 

 taries of the books of Hippocrates on epidemics, or popular diseases, 

 as they were called, it is asserted that pestilential maladies proceed 

 from a special condition of the heavens. These commentaries, at 

 one time attributed to Galen, have since been demonstrated to be 

 the production of his disciples. The long line of Greek, Latin, and 

 Arabic medical writers down to the time of Avicenna, the Moham- 

 medan physician, adhered to the teaching of Hippocrates and Galen, 

 and when they speak of contagion the term must always be under- 

 stood to mean contracting a disease by breathing altered air. The 

 masters of medicine of the middle ages held similar opinions. Ber- 

 nardo Gorgonio, professor of medicine at Montpellier, France, in 

 1300, and Arnaldo da Villanova, who lived toward the end of the 

 twelfth century, gave the name of pestilent fever to every deadly 

 fever and maintained the cause to be a corruption of the air. Gug- 

 lielmo Varignara, professor of medicine at Bologna in 1302, not only 

 denied the contagious nature of measles and smallpox but declared 

 that the buboes of plague were not contagious. Gentile, who died of 

 pest at Foligno, Italy, in 1348, believed that the poison of pest existed 

 in the air and was due to a putrefaction of this medium. John Godes- 

 den, a leading English physician of the fourteenth century, announced 

 the same views. De Chauliac, an eminent French physician of Avig- 

 non, who observed the terrible epidemic of 1348-1361, recorded 

 casually his idea that pest could be contracted by contact with the sick, 

 but assigned as a primary cause decomposition of the air due to the con- 

 junction of planets whereby a certain subtle substance is evolved capable 

 of producing epidemics. Another famous physician of those times, 

 Raimondo da Vinario, who was a spectator of the epidemics of pest in 

 1348-1361 and 1373, says that it is a very dangerous thing to have to 

 do with persons stricken with pest; that one person sick with pest 

 may infect an entire city; that those employed in public hygiene in 

 times of epidemic prevalence take the malady by contagion; that phy- 

 sicians more than any other class are likely to catch the disease; and 

 that monks are generally exempt from pest because they are isolated 

 in monasteries and thus free from outside exposure. Still there is not 

 room to believe that this master of medicine had any precise concep- 

 tion of the nature of contagion. Like so many others, he put his 

 faith in corruption of the air brought about by an influx of stars, 

 planets, and constellations, and in poisonous exhalations emanating 

 from the earth. The danger of contact with the sick he conceived to 

 be due to the air filled with pestilential poison that had been inspired 

 and afterwards exhaled by the victims of the disease. Da Vinario 

 held also that garments worn by the sick and other fabrics in close 

 contact with them contained the infective principle, and hence should 



