Vol. VI r. No. 161. 



THE AGRICULTURAL NEWS. 



207 



RATS AND THEIR DESTRUCTION. 



In all parts of the world the rat is regarded by 

 agriculturists as one of the most destructive pests 

 attacking their crops. The part played. by the rat in 

 disseminating various diseases, notabl}- bubonic plague, 

 which IS spread through the agency of tleas from the 

 body of the rat, is now well known, and furnishes 

 a further reason why no measure that may assist 

 towards the ultimate e.xtermination of the pest should 

 be neglected. 



In view of the attention now being given to the 

 question of rat destruction in these colonies, as a result 

 of the appearance of bubonic (jiague at Venezuela and 

 Trinidad, the following e.xtracts from a pamphlet 

 (Fa'Dners Bulletin ..'97) issued by the United States 

 Department of Agriculture, are worthy of note. Other 

 extracts from the pamphlet will be given in the ne.xt 

 number of the Aijricultwral Ncw^ : — 



Introduced into America about the year 1775 the brown 

 i-at [tbi.s i.s also the species that e.xists in the West Indies] has 

 supplanted and nearly e.xterminated its less robust relative, 

 the black rat, and despite the incessant warfare of man has 

 extended its range and steadily increa.sed in numbers. Its 

 dominance is due to its great fecundity and its ability to adapt 

 itself to all sorts of conditions. It breeds three or four times 

 a year and produces from six to twelve, and even more young at 

 a litter. Young females breed when only foin- or five months 

 old. The species is practically omnivorous, feeding upon all 

 kinds of animal and vegetable matter. It makes its home in 

 the open field, the hedge raw, and the river bank, as well 

 as in stone walls, jiiers, and all kinds of buildings. It destroys 

 grains when newly planted, while growing, and in the shock, 

 stack, mow, crib granary, mill elevator, or ship's hold, and 

 also in the bin and feed trough. It invades store and ware- 

 house and destroys fur, laces, silks, carpets, leather goods, 

 and groceries. It attacks fruits, vegetables, and meats in the 

 markets, and destroys by pollution ten times as much as it 

 actually eats. It carries diseasf germs from house to house, 

 and bubfjnic plague from city to city ; it destroys the farmers' 

 pigs, eggs, and young poultry, and damages foiuidations, 

 floors, doors, and furnishings of dwellings. 



Poisoning is the methotl most generally adopted for the 

 destruction of rats, and one of the cheapest and most effec- 

 tive poisons is barium carbonate, or barytes. This mineral 

 has the advantage of being without taste or smell ; and, in 

 the small (|uantities u.sed for poisoning rats and mice, is harm- 

 less to larger animals. Its action on rodents is .slow, but 

 reasonably sure, and it has the further advantage that the 

 animals before dying, if exit be possible, usually leave the 

 premi.ses in search of water. Its employment in houses, 

 therefore, is rarely followed by the annoying odour which 

 attends the use of the moi'c virulent poisons. 



The poison may be given in the form of a dough made of 

 une-fifth barytes and four-fifths meal, fait a more convenient 

 bait is ordinary oatmeal, with about OTie-eighth of its bulk of 

 barytes, mixed with water into a stiff dough, or the barytes 

 may be spread upon bread and butter or moistened toast. If 

 a single application of the poison fails to drive all rats from 

 the premises, it should be repeated with a i-hange of bait. 



Strychnine is a more virulent poi.son, but its action is .so 

 rapid that the animals often die upon the premi.se.s, a circum- 

 stance which prohibits its use in occupied dwellings. Else- 

 where strychnine may be employed with great succes.s. Dry 

 .strychnine crystals may be inserted in small pieces of raw 

 meat, Vienna sausage, or toasted cheese, and these placed in 



the rat runs ; or oatmeal may be wetted with a strychnine 

 syrup, and small quantities laid out in the .same way. 



Strychnine .syrup is prepared as follows : — Dissolve 

 V, oz. of strychnia sulphate in a pint of boiling water ; 

 aild a pint of thick sugar syrup, and stir thoroughly. A smaller 

 quantity of the poison may be prepared with a proportional 

 quantity of water. In preparing the bait it is necessary that 

 all the oatmeal .should be moistened with syrup. \Vlieat is 

 the most convenient alternative bait. It should be soaked 

 over uight in the strychnine .syrup. 



The two poisons most conunonly used for rats and mice 

 are arsenic and phosphorus, nearly all commercial prepai-a- 

 tions containing one or the other as a basis. While experi- 

 ments prove that rats have great powers of resistance to 

 arsenic, it may sometimes be used advantageously as an 

 alternative poison. Preparations of phosphorus sold by drug- 

 gists are often too weak to be effective ; and home made 

 mixture.s, when of sufficient strength, are dangerous, ms rats 

 may carry the baits into walls or crannies and thus cause 

 fires. F<jr these and other reasons the Biological Survey 

 does not reconnnend preparations containing phosphorus. 



For poisoning rats in buildings and yards occui)ied by 

 poultry, the following method is recommended : Two 

 wooden boxes should be used, one considerably larger than 

 the other, and each having two or more holes in the sides, 

 large enough to admit rats. The poisoned bait should be 

 placed on the bottom and near the middle of the larger box, 

 and the smaller box should then be inverted over it. liats 

 thus have free access to the bait, but fowls are excluded. 



RUBBER IN JAVA. 



The particulars given in the latest report of the 

 British Consul at Java indicate that a good deal of 

 attention is being given to rubber j)lanting in the 

 island, and that a considerable amount of British 

 capital is invested in the industry. The accompanying 

 extracts are taken from the report : — 



Considerable interest continues to be evinced in the 

 cultivation of rubbei'-i)roducing trees throughout the Dutch 

 East Indies, and the suitability of the climate and soil, 

 coupled with undoubted labour achantages which -lava 

 possesses over most other tropical countries, has resulted in 

 a steadily increasing trend of European capital towards 

 rubber enterprises in this country. 



According to statistics lately compiled, the capital of 

 British companies interested in rubber in the Dutch East 

 Indies, but domiciled in the United Kingdom, amounted to 

 nearly £1,-500, 000. Thi.s, however, does not include the 

 numerous conqianies formed during the last few years, also 

 with British capital, but domiciled in .Java, which may be 

 estimated at another £250,000. 



The first congress of rubber planters was held in ( )ctober 

 last, at which it was resolved to institute an Experimental 

 Station with nurseries, which should prove of valuable 

 assistance to rubber planters. The area at present under 

 cultivation is estimated at some 58,000 acres in .Java, 25,000 

 acres in Sumatra, and 7,000 acres in Borneo, of which most 

 of the older rubber and nearly all that is in bearing (say 

 one-half of the whole acreage) must be Ficun dastira, as the 

 cultivation of the Para variety dates only from 1905 onwards. 



At present, therefore, exports are still inconsiderable, 

 but in the course of a few years the Dutch East Indies 

 shoidd prove an important factor in the rubber markets of 

 Europe. 



