MALARIA. 423 



of entire security is not positively determined, but it has been 

 approximated as follows : in Italy, 400 to 500 feet ; in California, 

 1,000 feet ; along the Appalachian chain of the United States, 3,000 

 feet; in the West Indies, 1,400 to 1,800 feet; in India, 2,000 feet. In 

 any of such regions, however, malaria may drift up ravines to an 

 indefinite height. The agency of winds in transporting malaria for 

 considerable distances cannot be questioned. Lancisi, author of the 

 famous work "De Noxiis Pallidum Effluviis," published in Rome in 

 1717, attributes to such influence the fact of the Roman Campagna 

 having become unhealthy after the removal of the sacred groves 

 exposed it to the currents of wind blowing from the Pontine Marshes. 

 In later years, Barat accounts in the same manner for an epidemic 

 of malarial disease which arose in 1869 on the island of Reunion, 

 believing the poison to have been transported by the wind from Mau- 

 ritius, where such affections were then alarmingly prevalent. In this 

 instance none of the ordinary local causes could account for the out- 

 break. In four months, over 4,000 cases occurred in a popula- 

 tion of 23,000. Salvagnoli and other observers affirm that malarial 

 diseases increase in intensity, and penetrate farther inland on the 

 island of Sicily and in South Italy during the sirocco laden with 

 African miasm. 



With regard to the question, " Can di-inking-water act as a vehicle 

 for the introduction of malaria into the animal system?" a priori it 

 seems reasonable to suppose that such may be the case. If malaria, 

 be it a gaseous substance or an accumulation of minute organisms, 

 cannot pollute water, it differs essentially from other materials of 

 similar form with which we are better acquainted. But, in fact, we 

 have positive proof that malarial fevers may be due to drinking im- 

 pure water. Mr. Bettington, of the Madras Civil Service, states that 

 in that country it is notorious that the water may produce miasmatic 

 fever and affections of the spleen. He mentions villages placed under 

 similar conditions as to marsh-air, in some of which fevers are preva- 

 lent and in others not the difference resulting from the former drink- 

 ing marsh-water and the latter pure water. In one village there were 

 two sources of supply a tank fed by surface and marsh water, and a 

 pure spring; only those who used the tank-water contracted fever. 

 The celebrated instance related by Boudin is still more conclusive on 

 this point. In ] 834 there returned to Marseilles from Bona in the ship 

 Argo 120 soldiers, of whom 103 were seized with various forms of ma- 

 larial fever after drinking marsh-water taken on board at Bona. On 

 the other hand, the sailors of the same vessel, who had pure water, and 

 780 men embarked on two other vessels, remained well. The few sol- 

 diers on the Argo not attacked had purchased their drinking-water 

 from the sailors. Against such positive evidence as this the state- 

 ment of Finke that in Hungary and Holland marsh-water is drunk with- 

 out injury is of little value. 



