322 MOSQUITOES OF NORTH AMERICA 
cultivated. Then also, in further example, in quite recent years malaria entered 
and devastated the islands of Mauritius and Réunion, practically destroying for 
a time the productiveness of these rich colonies of Great Britain and France. 
“ Creighton, in his article on malaria in the Encyclopedia Britannica, states 
that this disease ‘ has been estimated to produce one-half of the entire mortality 
of the human race; and inasmuch as it is the most frequent cause of sickness 
and death in those parts of the globe that are most densely populated, the esti- 
mate may be taken as at least rhetorically correct.’ 
“Ts it possible to make any close estimate of the ratio between the number of 
deaths from malaria and the number of cases of the same malady? No per- 
fectly sound basis for such an estimate is apparent. In the English translation 
of Celli’s work on ‘Malaria According to the New Researches,’ published in 
London in 1900, it is stated that the mortality from malaria in Italy from 1887 
to 1898 varied from 21,033 in the first-named year to 11,378 in the last-named 
year, and the mean mortality for the period is assumed to be about 15,000. In 
1896 a count of the patients in the hospitals in Rome was made, and the mor- 
tality rate of 7.75 per thousand of the actual patients was established. Calculat- 
ing then on this basis, and at this rate, the number of cases per year for Italy was 
placed at about 2,000,000. According to this estimate, and with the average 
mortality for the United States of 12,000 as above indicated, the approximate 
number of cases for the United States would be about 1,550,000. It seems 
obvious, however, that Celli, in using the basis of hospital patients only, must 
have underestimated the number of cases for the Kingdom, since of the people in 
the country suffering from malaria the proportion entering the hospital must be 
relatively small. Therefore the death rate from malaria of malarial patients 
in the hospital must be greater than the death rate from malaria of the people 
who suffer from this disease in the whole country. In fact, so great must this 
discrepancy necessarily be that it would not seem at all unlikely to the writer 
if the number of persons suffering from malaria in Italy were in reality nearer 
3,000,000 than 2,000,000. 
“The same argument will hold for the United States, and more especially so 
since as a rule malaria in this country is of a lighter type than in Italy; in fact 
an estimate of 3,000,000 cases of malaria in the United States annually is prob- 
ably by no means too high. It will not be an exaggeration to estimate that one- 
fourth of the productive capacity of an individual suffering with an average case 
of malaria is lost. Accepting this as a basis, and including the loss through 
death, the cost of medicines, the losses to enterprises in malarious regions 
through the difficulty of securing competent labor, and other factors, it is safe 
to place the annual loss to the United States from malarial disease under present 
conditions at not less than one hundred millions of dollars. Celli has shown that 
in Italy the great railway industries, for example, feel the effect of malaria 
greatly. According to accurate calculations one company alone, for 1400 kilo- 
meters of railway and for 6416 workmen in malarious zones, spends on account 
of malaria 1,050,000 francs a year. The same writer states that the army in 
Italy from 1877 to 1897 had more than 300,000 cases of malaria. 
“The loss to this country in the way of retardation of the development of cer- 
tain regions, owing to the presence of malaria, is extremely great. Certain 
territory containing most fertile soil and capable of the highest agricultural 
productiveness is practically abandoned. With the introduction of proper 
drainage measures and antimosquito work of other character, millions of acres 
of untold capacity could be released from the scourge at a comparatively slight 
expenditure. These regions in the absence of malaria would have added millions 
upon millions to the wealth of the country. Drainage measures are now being 
initiated by the United States. Parties of engineers are being sent by the 
