Timbers. 



452 



[November, 1908. 



Owing to so many failures of the tubes 

 of virus used here being reported, 

 probably having been exposed to the 

 light or subjected to too much heat in 

 transit, or often through the instruc- 

 tions not being followed implicitly, the 

 island chemist was asked by the Board 

 of Agriculture and authorized by the 

 Government to try and prepare a virus 

 suitable for our conditions. This work 

 has been carried on at the Government 

 laboratory for a year past. Rats have 

 been caught and kept in cages and 

 inoculated with a Mexican rat virus, 

 which was said to be exceedingly viru- 

 lent, and also other preparations of virus. 

 This inoculation has been a success, as 

 the rats sicken and die ; other rats have 

 been inoculated, and consignments of 

 these have been let loose at the wharves 

 and stores in Kingston, at a plantation 

 in Manchester and at the hospital for 

 infectious diseases in Kingston, and 

 good results have been reported. This 

 work is still being carried on. It must 

 be mentioned, however, that, the best 

 effect found so far has been the inocu- 

 lation of the rats externally, i.e., the 

 preparation is inoculated into their 

 bodies, not swallowed. 



Inoculation is always more virulent 



than the taking of the same inter- 

 nally ; snake poison can be swallowed 

 with immunity, whereas the tiniest drop 

 entering the blood through the skin 

 kills a man in a short time. 



This is how the matter stands at 

 present, that inoculated rats have been 

 sent out from the laboratory to test 

 their effect, and good results have been 

 observed in sick rats coming out in the 

 daytime and dead rats lying about. But 

 the feeding of this virus to rats has not 

 given any of the desired results, that is, 

 it has not the effect of sickening them 

 and killing them. 



As this inoculation would be a cum- 

 brous way to work, we hope that it will 

 be found possible to prepare a culture 

 from the blood of the rat that can be 

 sent out in the way the preparations of 

 rat virus are to be set like ordinary 

 poisons. This is one of the most impor- 

 tant works that can be carried through 

 by the laboratory, for if we get an 

 effective virus it will save us thousands 

 of pounds per annum in cocoa alone. 

 Meantime, every method available 

 should be used— cats, dogs, traps, poison 

 and virus — and no effort spared to exter- 

 minate rats. — Journal of the Jamaica 

 Agricultural Society. 



