17 



Shilston (A. D). The Preparation of Caustic Soda and Sulphur 



Dip. — Agric. Journ., U. of S. Africa, Pretoria, vi, no. 5, Nov. 

 1913, pp. 746-749. 



During the course of a series of experiments which were carried out 

 to ascertain whether the caustic soda and sulphur dip exerted any 

 injurious effect on the health of sheep, departures from the correct 

 method of preparation, such as might easily occur on the farm, were 

 adopted, and the composition of the resulting mixtures tested. 

 Although solutions of caustic soda have a solvent action on wool, 

 compounds formed by the union of caustic soda and sulphur have no 

 such effect, and though after dipping the sulphur compounds in the 

 fleece may undergo oxidation, it is impossible for caustic soda to be set 

 free by scouring. In the formula recommended for preparing 100 

 gallons of this dip, 5 lb. of caustic soda should unite with 7f lb. of 

 sulphur, leaving 12 j lb. of sulphur undissolved, and if the given 

 directions are followed, little free caustic soda remains. Boiling water 

 should be used. If too much water is used, or if the water is 

 considerably below boiling point, little chemical action occurs, and 

 not only is such fluid dangerous to use, but it is also ineffective. The 

 fusion of the undissolved sulphur into lumps can be avoided by adding 

 the caustic soda slowly, or by pouring in a little more water when the 

 reaction is very energetic. Experiments were made to ascertain 

 whether a more uniform result could not be obtained by boiling the 

 ingredients, instead of relying on the activity of the chemical reaction 

 for the production of the necessary heat. The degree of reaction of the 

 caustic soda and sulphur can be determined by ascertaining the amount 

 of undissolved sulphur by testing the specific gravity of the fluid or its 

 alkalinity. It was found that boiling the correctly mixed fluid for 

 ten minutes is sufficient to complete the chemical reaction. If the 

 mixing has been improperly carried out, boiling is the surest means of 

 producing a fluid of uniform composition. Boiling water for mixing 

 the sulphur paste is not necessary if the mixture is to be boiled 

 afterwards. 



Mosquitos and "Millions." — Agric. Journ., U. of S. Africa, Pretoria, 

 vi, no. 5, Nov. 1913, p. 829. 



The Anti-Malarial Association was instrumental in importing a 

 consignment of the West Indian fish, known as " Millions," with a 

 view to acclimatising them in South Africa. The two lots of fish, 

 consigned to the Transvaal Trout Acclimatisation's Hatcheries at 

 Potchefstroom, and to the Pongola Rubber Estate Company in Zulu- 

 land, ultimately disappeared. The fish consigned to the Stellenbosch 

 Hatcheries have made excellent progress, and the Curator is hoping 

 to be able to distribute small lots of fish to suitable places during the 

 coming season. 



Russell (H.). The Flea.— Camb. Manuals of Science and Literature, 

 Camb. Univ. Press, 1913, 125 pp., 9 figs. 



The author says in his preface that this book is intended- toLgive in 

 plain language some account of a small but nofe\yoithy' groir^ of 



(C14) Wt.P.11/12— 2G.3.13. 1,500. 2.14. B.&.F.Xtd. G 



I 



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