81 



sliould be done with a 2| per cent, solution of potash soap. Equally 

 satisfactory results were obtained with medical (soda) soap (Sapon. 

 med. plv. of the German Pharmacopoeia) in 1| per cent, solution. 

 It is not probable that such weak solutions will damage household 

 goods, but tests might be made in the houses of the natives, or in 

 cowsheds, etc. The author refers to his former statement that the 

 toxic properties of pyrethrum are enhanced by comparatively small 

 cpiantities of soap. It has since been found that a number of other 

 substances acquire marked activity through the addition of soap, 

 whereas otherwise they need to be employed in such a degree of con- 

 centration as to render them unpractical. Formaldehyde may be 

 instanced as one of these. A solution of If oz. commercial formalin 

 in 12 pints water causes great irritation to the lungs, and is innocuous 

 to the insects. A solution of 10 drams spirit, sapon. kalini (Pharm. 

 derm.) in If pints water is also innocuous, but if the ingredients in 

 both be mixed together, less than one-half of the quantities given above 

 will kill the insects instantly. Any moderate traces of the smell of 

 formalin are easily dissipated if a small quantity of ammonia be 

 allowed to evaporate in the room. The following conclusions are of 

 practical value : (1) Soaps form a valuable basis for culicide spray- 

 solutions ; (2) Complete success was obtained in the laboratory with 

 the following: {a) 2 fluid oz. spirit, sapon. kalin. (Pharm. Germ.) 

 in 1| pints water ; (b) 8 drams medical soap (Sapon. med. plv. of the 

 Pharm. Germ.) in 1| pints water ; (c) 8 fluid scruples spirit, sapon. 

 kalin. in 1 quart water containing 15 drams of commercial (35 percent.) 

 formalin; (d) 3 drams sapon. med. plv. in If pints water 

 containing 11 .drams of formalin. (3) With 60 per cent, alcohol, 

 33 per cent, stock solution of sapon. med. plv. may readily be prepared 

 on the water-bath. (4) Soft water (rain water, when obtainable) 

 must always be used ; where water has more than 15 degrees of 

 hardness more stock solution must be added. (5) Soap solutions 

 containing formaldehyde act most energetically on mosquitos ; in 

 more concentrated forms they kill Muaca domestica and Stomoxijs ; 

 they may perhaps be of use against Glossina morsifans and G. palpalis, 

 or ticks. (6) As soap solutions containing formaldehyde are powerful 

 bactericides, they will also serve a disinfecting purpose. (7) These 

 solutions have an advantage over the strong smelling Crysol solutions, 

 inasmuch as their after-smell may easily be removed by ammonia. 

 (8) The means indicated are so cheap as to admit of universal and 

 thorough application. 



RiCARDO (G.). Tabanidae from Formosa. — Supplementa Enlomologica. \j 

 Berlin, no. 3, 27th Jan. 1914, pp. 62-65. /\ 



Two new species are described in this paper, T. fulvicinctus and T. 

 quinquecinctus. 



Edwards (F. W.). On the Oriental Culicid Genus Leicesferia, Theo- 

 bald. — Bull. Entom. Research, London, iv, pt. 4, Feb. 1914, 

 pp. 255-263. 7 figs. 



The author gives a systematic account of the species of Leicesteria, 

 including in this genus the species for which Dr. Leicester formed 

 the genus Chaetomyia, and those placed by Theobald in the genus 



