Vol. XI. No. 255. 



THE AGRICULTURAL NEWS. 



■*! 



Agricultural Pupils at the Dominica Botanic 



Station. 



Information has been received from Mr. J. Jones 

 Curator of the Botanic Station, Dominica, that, after 

 notices appearing in the (J§irial Gazette and the local 

 press, nine applications were received at the Botanic 

 Station for three vacancies, as pupils under the new 

 scheme of agricultuial instruction (see Agricultural 

 JVeivs, Vol. X, p. 2-12). On January 8, seven of the 

 applicants presented themselves for e.xaminatioD, and 

 as a result of this the four following have been selected 

 as pupils on probation: F. J. Lawrence, La Plaine 

 (75 per cent.); S. J. Jules .Soufri('re, and V. J. Laronde 

 La Plaine (70 per cent, each); E. Joseph, DubJanc 

 (65 per cent.) 



Spraying to Kill Weeds. 



Attention is drawn, in Circular No. 102 of the 

 Ohio Agricultural Experiment Station, to the obvious 

 fact thac in spraying for killing weeds the sub- 

 stances u.sed must be such as will destroy the weeds 

 without causing injury to the crop that is being grown. 

 A useful circumstance in connexion with the matter is 

 that it has been found that the sprays used for weed 

 destruction injure nearly all crops and weeds possess- 

 ing broad leaves, while all weeds with narrow leaves 

 are most likely to escape injury. It follows from this 

 that such plants as alfalfa and soy bean will be killed 

 by the substances which destroy broad-leaved weeds. 

 while sedges and various grass werds will not be destroy- 

 ed by spraying with solutions that are not injurious to 

 the grasses and cereal crops. The matter is brietiy sum- 

 marised by saying that, in Ohio, weed sprays, when 

 properly adat.tpd, should be available for the destruc- 

 tson of the largtr p(]rtion of the pasture and grain 

 field-infesting weeds, when the methods are rightly and 

 economically developed. 



Among the spray solutions tested, the following 

 have been found most useful : — 



Common salt solution, containing 3 lb. of salt to 

 the gallon of water, applied at the rate of 50 to 75 

 gallons per acre. 



Iron sulphate (copperas) solution, containing J- to 

 2 lb. of iron sulphate to the gallon of water; that is 

 100 lb. of iron sulphate to 52 gallons of water. This is 

 ' employed at the rate of 50 to 75 gallons per acre. 



Calcium chloride solution of the same strength as 

 the salt solution, and used at the same rate. 



Sodium arsenite solution, at a strength of li lb. 

 of sodium arsenite to 50 gallons of water. 



Copper sulphate (blue vitriol) solution at a strength 

 of 8 to 10 lb. in 50 gallons of water; this is applied at 

 the rate of 40 to 50 gallons per acre. 



In commenting on these solutions, the circular 

 points out, among other matters, that sodium arsenite 

 is a very active poison and rather dangerous to use, 

 and that the tests have shown that calcium chloride is 

 very effective, but appears to be slightly inferior to 

 common salt. 



In dealing with the application of weed sprays, the 



circular states: ' The chemical solutions used as sprays 

 to kill weeds should be applied, as all other sprays, by 

 means of suitable spray nozzles, which deposit the so- 

 lution as a fine mist upon the surface of the leaves of 

 the plant. One can use almost any good spray pump 

 which will give good pressure, and direct the spray 

 nozzles after the manner used in orchards and vine- 

 yards, or the traction potato sprayers can be so adjusted 

 as to spray the whole area, instead of the row spaces 

 only, thus applying the spray more satisfactorily.' 



Oil from Tobacco Seed. 



A note in the Journal d' Agriculture Tro2)icale 

 for November 1911 states that the suggestion is being 

 made in the United States of America that tobacco 

 shall be cultivated with the object of obtaining seed 

 for the production of oil. The oil content of the seed 

 is about 15 percent, of its weight: its quality is very 

 good and it is easily obtained. In its production, alter 

 being bruised, the seeds are mixed with a certain quan- 

 tity of warm water, and the paste made in this way is 

 submitted to great pressure. The oil thus expressed 

 is obtained mixed with impurities, and in order to 

 eliminate albuminoid matters by coagulation it is 

 heated gently, when these matters sink to the bottom, 

 the pure oil being left floating above them. 



The growing importance of drying oils renders the 

 subject of great interest, especially where the seed may 

 be utilized as a by-product in the production of leaf. 

 It remains to be seen, however, if the growing of tobacco 

 for its leaves has any effect on the oil content of the 

 seeds. 



The Absorption of Fat in Relation to Water- 

 Drmking. 



An abstract is made, in the Experiment Station 

 Ih'cord, Vol. XXV, p. 268, of a paper dealing with 

 recent work that has been conducted for the purpose 

 of .ascertaining the effect of copious and moderate 

 water-drinking with meals on the absorption of fat by 

 the human body. 



The experiments were made with subjects placed 

 on a uniform diet, small amounts of water being taken 

 for the first and last periods of the experiment, the 

 quantities in the intermediate time being large. 



With the large amounts of water, the quantity of 

 fat absorbed into the system increased; there was 

 a reduction in the proportion when the amount of water 

 .allowed was halved. 



The better digestion and absorjrtion of fat, when 

 large i[uantities of water were drunk are attributed to 

 any or all of the following causes: (1) increased secre- 

 tion of gastric juice and of pancreatic juice; (2) increas- 

 ed acidity of the contents of the small intestine, which 

 brings about a greater secretion of pancreatic juice 

 and bile; (3) an increase in peristaltic action; (4) greater 

 blood pressure, due to rapidly ab.sorbed water; (5) gieater 

 ease in the breaking up of the fat, on account of the 

 presence of large amounts of water. 



