| Show TO KILL DILL ILL PESTS WITH WAR GAS I Experiments on the use of oi poison polson gases for exterminating obnoxious I birds rodents and insects will be undertaken undertaken un un- this fall tall by the U. U S. S biological biological biological bio bio- un-I un logical survey in cooperation with the chemical warfare service The method will first be tried on blackbirds blackbirds blackbirds black black- I birds in m the Imperial valley of ot Gall Calf lot fornia nia In that region we are told by Chemical and Metallurgical Engineering En En- I New York these birds are arc said to do least worth of damage Ea l rear It Is impossible ble bie to destroy them with poisoned baits but as th they y roost on the reeds in the marshes It ft is thought that they can be lie killed by a gas cloud at night when the wind Is favorable Says the paper named above II The blackbirds are migratory and return to the same places year after year It is thought that a big killIng killing kill kill- Ing in a certain locality will probably free it of ot the pests for many years A few other birds in the blackbird- blackbird Infested marshes will be killed at the I same time but the department belIeves believes believes be be- that these local birds will soon reach their normal numbers again Arrangements also are being made b by the biological survey with the chemical warfare service for investigating Investigating investigating gating the possibility of using poison poison poi poi- son gases on such ro rodents rodents rodents ro- ro I dents as rats prairie dogs I squirrels and woodchucks Tests on I pocket gophers and squirrels ground-squirrels I by these two cooperating branches of ot the government in California show I. I that chlorine may be used usell with good results if it handled properly The chemical warfare service used phosgene phosgene phosgene gene on rats in Porto Rico with i promising results Some of these war gases will be compared with carbon carbon car car- car I bon for the killing or wo woodchucks and other rodents in their burrows o |
