﻿18 The Philippine Journal of Science i9u 



formulas. For instance, for the quarter ending June 30, 1913, 

 there were 166,237 poisoned baits set and the rats found poisoned 

 averaged for each 100 baits 0.72, from which it appears that 

 the rat poison ranks lowest in efficiency, but perhaps highest 

 in economy. In view of the fact that the original cost of the 

 cage trap is many times that of the spring trap and that 

 the cost of maintenance is very high, it will be apparent that 

 the spring trap is by far the more economical as well as more 

 effective of the two. 



MANILA RAT-PROOFING REGULATIONS 



On account of the presence of plague in Manila, it was deemed 

 most opportune to insist not only upon rat proofing in the 

 buildings and areas which were infected, but to require rat- 

 proof construction in all buildings which were to be erected 

 in Manila in the future, and the following regulations have 

 now been enforced during the past six months. 



All proposed new buildings of whatever nature, whether fac- 

 tory, stable, garage, bodega, warehouse, private dwelling, or any 

 other class of building, shall be designed and erected so as to 

 have no hollow ceilings, walls, columns, stairs, floors, etc. This 

 shall also apply to repairs or alterations to existing structures. 

 Whenever a ceiling or hollow partition is removed, the same shall 

 not be replaced. 



Architects, builders, and others concerned are requested to 

 incorporate the following paragraphs in plans and specifications 

 for future buildings of this nature. 



For the purpose of preventing the entrance and harboring of 

 rats etc., this building will be constructed (or repaired) without 

 hollow walls, hollow ceilings, hollow stairs, hollow floors, hollow 

 columns, etc. 



All walls, with the exception of solid wood framing, within 

 1 meter of the ground will be of concrete, brick, stone, mortar, 

 or other material proof against the incursions of rats and will 

 extend below the ground to a depth of at least twice the thick- 

 ness of the wall. 



KINDS OF RATS CAUGHT IN MANILA 



From the beginning of the outbreak until September 30 there 

 were 68,667 rats caught. At the outset, an effort was made to 

 classify the different species of rats, but owing to the difference 

 of opinion among those charged with the work as to the correct 

 identification of many of the rats it is not deemed that the figures 



