218 



Mendy (J. B.). La Sarna humana y la Sarna bovina. Su Naturaleza, 

 Curaci6n y Extirpacldn. [Human and Bovine Scabies. Its Nature, 

 Cure and Extirpation.] — Anales Soc. Rural Argentina, Biienos 

 Aires, lii, no. 4, April 1918, pp. 216-226, 12 figs. [Received 

 23rd September 1918.] 



This paper is a resume of the facts relating to the Acarids producing 

 mange in man and cattle. Formulae for the usual remedial solutions 

 are given, together with practical instructions for erecting dipping 

 tanks. 



Sinclair (J. M.). Management of Dipping Td^n^s,.— Rhodesia Agric. 

 Jl., Salisbury, xv, no. 1, February 1918, pp. 32-33. 



Experience has shown that niany owners and managers of dipping- 

 tanks find a considerable difficulty in adding water, or dip, to the liquid 

 in the tank, so as to bring it back to any desired strength. Further, 

 the tendency being to err on the side of safety, it often follows that 

 the strength of the dip is diminished to such an extent as to be 

 ineffective. 



Attention to the following practical points should render easier 

 the management of a tank : — (1) On filling the tank, the water should 

 be measured by a 200-gal. or other convenient measure ; (2) from 

 the 3 ft. 6 in. level, the volume, inch by inch, should be carefully 

 recorded and marked on the wall of the tank, or, preferably, on a 

 measuring rod ; (3) the level should be recorded after each dipping 

 and again before the following one ; (4) loss due to evaporation should 

 be replaced by water only ; (5) increase due to rain or flood-water 

 should be standardised by the addition of dip ; (6) the quantity of 

 solution in the tank should be carefully estimated at the time when 

 a sample is taken for analysis, otherwise the alteration in strength 

 required as the result of analysis will be impossible ; (7) in forwarding 

 samples of dipping solutions for analysis, care should be taken that 

 the bottles and utensils used for filling them are free from extraneous 

 arsenic, 



Thibault, Junr. (J. K.). U.S. Bur Entom. Vegetable Powder as a 

 Larvicidein the Fight against Mosquitoes. — Jl. Amer. Med. Assoc, 

 Chicago, III, Ixx, no. 17, 27th April 1918, pp. 1215-1216. 



Experiments made in order to find a larvicide cheaper than crude 

 oil and available in water -gardens, outdoor fish-pools, rice-fields and 

 other places where oil is unsuitable, have resulted in the discovery of a 

 material which is an efficient substitute under most conditions. This 

 larvicide consists of various vegetable powders, including .pyrethrum. 

 The latter is too expensive, and as its action is purely mechanical, 

 experiments were made with weeds and grasses of nearly every species 

 growing in the neighbourhood ; these dried and reduced to a 

 sufficiently fine powder gave very good results. No particular 

 species need be chosen. A good powder should spread quickly and 

 evenly even if thrown in by the handful. It is however more potent 

 when apphed in the form of a spray. The covering capacity should 

 be from 3,500 to more than 4,000 square feet per pound of powder. 

 It is only efEective for a few minutes, but is so deadly to the larvae 



