Vol. XVI. No. 403. 



THE AGRICULTURAL NEWS. 



.345 



IPlants Poisonous to Live Stock. 



Nature for August 23, 1917, reviews a book by 

 H. C. Long with the above title. This book deals 

 with plants poisonous to livestock in the United King- 

 dom, but some of the author's conclusions apply to any 

 part of the world. 



Poisonous plants differ widely in degree of harm- 

 fulness. Probably, under ordinary conditions, many of 

 the plants regarded as pjisonous are almost harmless. 

 Animals in their natural state appear to avoid these 

 poisonous plants, and to be less readily poisbned than 

 are domesticated animals. Again, some animals seem 

 to have a depraved appetite for unusual food-plants. 

 The author quotes a remark of an American writer 

 that 'there seems to be no way of accounting for the 

 appetite or taste of stock.' This statement is perhaps 

 especially true of sheep, which will eat greedily on one 

 day plants that they could scarcely be persuaded to 

 eat on ihe following day on the same pasturage. 

 The poisonous properties of a plant are often affected 

 by conditions of soil, climate, and cultivation. So 

 much so that a plant is sometimes regarded as harmless 

 in one country, and poisonous in another. Again, 

 a plant may be poisonous in all its parts, or one part 

 alone may be toxic. Frequently also there are varia- 

 tions in the poisonous character according to the season, 

 or some paros of the plant may be much more toxic 

 than others. 



Cotton and Wool Spun from Glass. 



An interesting account, taken from a report of the 

 United States Consul in Venice, is given of the makino- 

 of these articles in the India Rubber Journal, 

 August 2.5, 1917. The article referred to says that 'Dhe 

 spinning of glass for commercial uses has developed 

 into an important industry in Venice. . . . The spun o-lass 

 is marketed in three forms — hanks of spun glass thread 

 of straight fibre called glass cotton, masses of spun glass 

 curled fibre called glass wool, end either of the above 

 qualities pressed into sheets or pads from '-inch to 

 J-inch in thickness that resemble white felt pads. 

 At present the principal use made of this product is for 

 insulation, and especially for making separators for 

 accumulators of electricity, but the glass wool would 

 serve admirably for making artificial hair, and other 

 purposes, and in the pad form it serves as a hyo-ienic 

 filter. 



'The processes of manufacture are simple. Solid 

 glass rods abjut 2 feet 6 inches long and the thickness 

 of a lead pencil are made of pure American soda that 

 contains no adulteration of lead or other metal. The 

 absence of lead and adulterations gives the quality ot 



perfect flexibility to the fibre On a desk is mounted 



a Bunsen burner or gas flame and blowpipe. By the 

 side of the desk is mounted an ordinary bicycle wheel 

 minus the rubber tyre, that revolves rapidly and 

 regularly at rhythmic speed under power furnished 

 by a sm^ll electric motor. The hank of thread 

 o:i the wheel, when it has assumed the dimensions 

 of a bicycle tyre, is taken off. . Separated with the 

 fingers it curls and fluffs out like wool, if the thread is 



suftciently fane. It is packed in the hank as glass 

 cotton, in the fluff as glass wool, and In the compressed 



lorm as glass wool or cotton according to the fineness 

 or the nbre. 



Influence of Limestone on Crop Yield. 



It is generally assumed that burnt or slaked lime 

 IS the most efli'cient form in which to employ lime for 

 agricultural purposes in applications to the soil. Recent 

 investigations have been m*de as to whether finelNr 

 ground limestone may not be equal, if not superior ia 

 value lor the purpose to the caustic forms of lime 

 An account of investigations and experiments in this 

 direction IS given by Nicholas Kopiloff, Research 

 ^e low Rutgers College, New Jersey, in Soil Science, 

 July l.Jlr. In the experiments limestone was oround 

 to various degrees of fineness, from passing through 

 a sieve having twenty meshes to the inch to passin<^ 

 through one having 200 meshes to the inch. 



It would seem that the following points amongst 

 others, have been established by the experiments- 

 (1) An increase in fineness of division of pulverized 

 huiestone is responsible for a proportional yield of crop 

 on several soil types. (2) There was little choice m 

 effect between burnt lime and 200- mesh limestone. 

 (3) An increase in fineness of division in pulverized' 

 limestone increases the activity of the bacteriological 

 processes of ammomfication, nitrification, and nitrogea 

 fixation. " 



In general the conclusion is reached that an in- 

 crease in the fineness of division of pulverized limestone 

 IS reponsible for a proportionate increase in crop yield 

 as well as for exerting a beneficial effect on the 

 chemical foctors in the soil. In these respects 200- mesh 

 hmestone may be regarded as effective as burnt lime. 



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How to Keep Coco-nut Butter Firm. 



Tlie Jouinalofthe Jamaica Agricultural Society, 

 August 1917, gives directions for the construction of aa 

 iceiess refrigerator which can keep coco-nut butter from 

 6 to 10^ below the ordinary shade temperature. This 

 device can be used to keep any article that depends on 

 a low temperature for its well-being. 



A series of shelves is made to fit into upright legs, 

 leaving the sides open. The most convenient°size for 

 these shelves is probably about 18 inches square. The 

 legs are placed in a tub— any ordinary zinc tub will do; 

 and on the top of the shelves a fairly large pudding 

 pan is put. The sides are covered with a piece of 

 flannel or flannelette, cut, and sewed to fit the whole 

 construction. The lower end of the cloth hangs dowa 

 into the tub, and the upper ends, which must be about 

 9 inches taller than the structure, fall over into the 

 pudding pan. Water is now put into the two vessels 

 and capillary attraction causes an upward and down- 

 ward movement of water, which evaporates very 

 quickly, thus lowering the temperature. It will be 

 found that the upper vessel will have to be refilled two 

 or three times a day. Not only for keeping coco-nub 

 butter firm, but for keeping meat, and milk, and 

 ordinary butter this refrio;erator will be found of service 

 in any place where it is difficult' to obtain ice. 



