Vol. XVII. No. 42-5. 



THE AGEICULIURAL N£\VS. 



■2Vi 



that the zinc has also a germicidal effect. An article 

 in the iarjcei, June 30, 1917, contribute<l by Dr. H. ti 

 Scott, (Jovernment Bacteriologist in Jamaica, and 

 Dr. \V. W. Jameson, writing in collaboration, makes 

 this quite clear. It is an account ofvery careful inves- 

 tigation and experiments on the supply of drinking 

 water of a small depAt in the Aldershot command of 

 some ■2()() men, which was found to contain from -ly to 



4-72 parts of metallic zinc per 100,000, that is trom 

 1-7.5 to 0-33 grains of zinc per gallon. The following 

 are the conclusions arrived at. 



During a period of two years this was the sole 

 source of supply of drinking water, and no disturbance 

 of health resulted. 



In one household the disappearance ot a per- 

 sistent condition of ill health, attributed locally to a 

 contaminated water-supply, coincided with the laying 

 on of a water containing considerable Tjuantities ot 



zinc. , ,. , , 



The number of organisms of the coli type develop- 

 ing at blood-heat from the well-water used as a control 

 was materially greater than was found in the water 

 after it had taken up from 3 to 4 parts of metallic zinc 

 per 100,000, and remained in storage for two days at 



most. 1^-1 



To ascertain whether this effect on bacterial 

 growth might be due to the zinc content of the water, 

 various experiments were undertaken, from which it 

 appeared: (1) that from 3 to i parts of zinc sulphate 

 were sufficient after twenty-four hours contact to 

 inhibit, if not to destrov, organisms in numbers con- 

 siderably exceeding those likely to be found m any 

 ■drinking supply, and (2) that even as small an amount 

 of zinc sulphate per 100,000 as TS renders such water 

 practically sterile in forty-eight hours. 



The use of water containing zinc naturally in 

 solution as a carbonate, shows analogous results, but 

 the reduction of organisms after the tirs^ twenty-four 

 hours is not so great as by the use of the sulphate, 

 though complete sterilization does appear to take place 

 between forty-eight and seventy-two hours. 



^^^^m--^ -^ 



New Products from South Africa. 



The results of investigations by the Imperial 

 Institute of a large number of South African products 

 were considered by the Committee for South Africa 

 and Rhodesia at a recent meeting under the Chair- 

 manship of the High Commissioner for the TTnion, 

 the Right Hon. W. P. Schreiner. 



A small consignment of liquid ostrich eggs was 

 recently sent from South Africa for examination at the 

 Imperial Institute, with a view to ascertaining its 

 value as a substitute for liquid hens' eggs in confec- 

 tionery The material proved to be similar in com- 

 position to the commercial liquid hens' and ducks 

 egcrs The opinions of confectioners were favourable, 

 and another consignment of the eggs is being obtained 

 from the Union for further trials. There would appear 

 to be a good opening for this material in the ITnited 

 Kingdom, if it can be exported in quantity. 



Owing to the great scarcity of vegetable waxes ot 

 all kinds in the United Kingdom at present, it -seems 



likelv that there would be a good market for increased 

 supplies of the sugar-cane wax which is being extracted 

 from sugar-cane wasDe on certain estates in Natal. 

 The shortage of tin-plate has led to the manufacture 

 on a large scale in the United Kingdom of card-board 

 containers for jam, syrup, and other foodstuffs. These 

 containers must be coated with a film of hard wax to 

 rentier them impermeable to the semi-tfuid contents', 

 and sugar-cane wax appears to be quite suitable for 

 this purpose. 



The Chicle Gum Industry 



Chicle gum is the latex of a variety of ohe sapo- 

 dilla (.4c/ims .S'a/>ota) which grows wild in large num- 

 bers in that part of Guatemala bordering on British 

 Honduras. The chicle resources of that country are 

 declared to be practically inexhaustible, although no one 

 IS permitted to gather the gum without a government, 

 concession. A large tree will yield as much as 100 ft. 

 of the crude gum, and smaller and younger trees less m 

 proportion. The gum is boiled in large iron pots, trora 

 which it is poured into wooden boxes with a capacity 

 of 80 ft each. The gum hardens in these boxes, and ib 

 IS carried in this form to the shipping seaport, where 

 it is removed from the boxes and packed in sacks tor 



export. . ,. 



The bulk of the product is shipped from Belize. 

 British Honduras, to the United States, wherr it meets 

 with a ready market for the manufacture of chewing 

 gum. 



The Mixing and Preservation of Manures. 



As IS well known, difficulties sometimes arise froiu 

 want of information as to the descriptions of manure 

 which may or may not be brought into association^wiih 

 each other. In an article appearing in the boiUfb 

 African Siujar Journal, April U>18, an endeavour is 

 made to clarify some of the doubtful points, and thus 

 to reduce fertilizing to practice. 



First emphasis is placed on the necessity, when 

 purchasing a manure, for insistence on a guarantee of 

 its composition as determined by analysis. Then it is 

 suggested that artificial manures should be mixed witti 

 about three times their weight of dry loam, and dis- 

 tributed evenly. , , , , , jj 4 , 



Lime, it is advised, should never be added to a 

 manure containing sulphate of ammonia, or blood and 

 bone manures, as m such cases loss of nitrogen results; 

 and when lime has been applied to the land, do nob 

 vise manures until three weeks afterwards. 



When mixing various fertilzers together, such mix- 

 tures must be avoided as would lead to decomposition, 

 as for instance, ammonia sulphate mixed with lime or 

 wi'th Thomas phosphate, or superphosphate with nit- 

 rate of soda: or which may cause caking, as mixing 

 kainit with Thomas phosphate, or with superphosphate. 

 All manures should be in a dry, friable condition, 

 and must be free from hard lumps, and for this reasoa 

 must be kept in good dry bags, an.l in covered sheds. 



