76 THE AMERICAN MONTHLY (Mar 
vigorous enough to prevent the diplococci invading the 
lungs, but put such a person under bad sanitary condi- 
tions, or depress his vitality, and the microbes are not 
phagocyted—they invade the lungs and pneumonia and 
death follow.’—Address at Havana, Feb. 7, 1901. 
Malaria. 
LORD LISTER. 
Before the Royal Society. 
The subject has now reached a stage at which it may be 
not unfitting to refer briefly to what has been accomplish- 
ed. The term “malaria” implied the belief that some vi- 
tiated state of the atmosphere was the cause of the dis- 
ease. But the knowledge gained of late years of the par- 
asitic nature of infective disorders pointed clearly to such 
an origin of the intermittent fevers, as the various mani- 
festations of malaria have been termed. Accordingly dil- 
igent and long-continued search was made in the water 
and the soil of malarious districts in Italy for the sus- 
pected living agent, but without success. The discovery 
was made in 1880 by Laveran, a French army surgeon 
stationed in Algiers, who observed in the red blood cor- 
puscles of malarious patients what he regarded as adven- 
titious living organisms ; not of vegetable nature like the 
bacteria which constitute the materies morbi of so many 
infective diseases, but a very low form of animal life. In 
what he believed to be the youngest condition of the or- 
ganisms, they appeared in the red blood-dises as tiny specks . 
of colorless protoplasms, possessing amoeboid movements. 
These growing at the expense of the red corpuscles which 
they inbabited, consumed them more or less completely, 
at the same time depositing in their own substance a pe- 
euliar form of dark brown or black pigment, such as had 
long been known to form eharacteristic deposits in the or- 
gans of malarious subjects. As they grew they assumed 
various forms, among which was what Laveran termed. 
—— 
ond a” To 
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