﻿IX. B, 1 



Heiser: Plague in the Philippines 



17 



FUMIGATION OF VESSELS 



In the appendix will be found complete tables, by years, show- 

 ing the number of vessels fumigated with sulphur in Manila 

 since 1903 and the number of rats found on them. All of the 

 foregoing data have been made into a consolidated table, and 

 it is of interest to note that there is little difference between 

 the number of rats killed per vessel as shown by the consolidated 

 table as compared with the table for any one year, which is 

 strong evidence that vessels must be fumigated at frequent inter- 

 vals, because vessels that have been regularly fumigated are just 

 as liable to harbor rats as vessels that have not been fumigated. 



EFFECTIVENESS OF THE VARIOUS MEASURES EMPLOYED IN 



CATCHING RATS 



The ratio maintained in catching rats with two types of traps 

 is well shown in the following table, a perusal of which will 

 show that for the three months ending June 30, 1913, there 

 were 120,565 spring or snap traps set and that for every 100 

 of this type of trap set there were caught 6.9 rats. During the 

 same period, there were 47,075 wire-cage traps set; the total 

 number of rats caught was 339, which gives 0.72 rat caught for 

 each hundred traps set. For the quarter ending September 13, 

 130,627 spring or snap traps were set and 9,753 rats caught, 

 which gives 7.47 for each 100 traps set. During this period, 

 40,621 wire-cage traps were set and 395 rats were caught, which 

 gives 0.97 rat caught for each 100 wire-cage traps set. 



Table II. — Relative efficiency of poisons and different kinds of traps used. 



Kind of trap or poison. 



Quarter ending June 30. 



Quarter ending September 30. 



Number 

 set. 



Number 

 of rats 

 caught 

 or poi- 

 soned. 



Percent- 

 age. 



Number 

 set. 



Number 

 of rats 

 caught 

 or poi- 

 soned. 



1 



Percent- 

 age. 





120, 565 

 47, 075 



166, 237 



8,377 

 339 



1,216 



6.900 

 0.720 



0.731 



130, 627 

 40, 621 



7,753 

 395 



7.47 

 0.97 





Poisoned bait: 



Bacon and coconuts 





177, .309 



216 



0.12 













160 



2,889 



316 



5 



3,818 



297 









Number of rats found dead from othf^r paiiRpq 















No accurate account was kept of the various forms of rat 

 poison used. Bacon, coconut, and rice were used in different 



124293-^2 



