75 



OiEMSA Hj.). Das Muckenspiay verfahren im Dienste der Bekamp- 

 fung der Malaria und anderer durch Stechmiicken iibertragbarer 

 Krankheiten. | Spr;iyiii<4' ;is :i nicaiis of ijrcveiiiiii;^' M:il;iriii 

 aij(l other diseases (-arried by l)iliii<>' (lies. J — Anii. j. Sdn/J.s- 

 u. Trap. Hiiu, xvii, no. (J, Manli \\)\'A, \)\). IHl-liJO. 



'Die aiillior poiiils out llial lln' picsciil iiietliods in use lor llie 

 suppression ol malaria and other inseet-bonie diseases are uJi 

 directed to. the jiicveiilion ol' the breeding' ot tiie disease-carrier 

 and that ]ittl(! is done by way ol attack on the insects themselves. 

 Stendel (Arch. /. Sclii'jjs- i, . Trop. II mj., lUU, p. 121) called 

 attention to this nej^lec^t of a very iniporlant means of jtrevcnl in<^-, 

 (ir at least d i ni i ii ish in<^-, the spread of malai'ia. Careful examina- 

 tion of Jiumerous jiative huts at (jama, (Kamerun) l<'<l lo tin- 

 discovery that Jarj^c numbers of Anoi)hcliiies passc<l the dry 

 season i]i these .huts in a state of tori)or, and lie ar<>ucd that if 

 these (a lar^e majority of wiiich aic probably infected) couhl b(^ 

 destioyed, the niunber of infecticjn carjieis would be very sensibly 

 diminished. 'V\w, practical difhculty lies in the devisin<^- of tin! 

 means foi- their destruction, as fiim it^at ion is not practicable, by 

 leason of the construction of the huts. The author and Miihl.ens 

 experimented in Hamburg' in liJll with si)rays on nioscjuitos 

 hibernating' in cellars, etc., with veiy good lesults. In order to 

 wet the insects effectively the fluid n)ust be atomised; they legard 

 11,,. piinciiih' of the ordinary scent diffuser as not the best for the 

 a])j)aiatus re(juJred, and a specially constructed no/zle is recom- 

 mended for this purpose. The choice of the fluid insecticide to 

 be used is somewhat limited in practice, inasmuch as human 

 beings are concerned and the (fleet iiiion them has to be con- 

 sidered. Mixtuics c(jntaining' ])hej)()l and cresol, for example, 

 were found, when diffused in this way, not only to leave a very 

 persisteni and penetrating odour, but to be intensely irritating 

 to the human res])iratory tract; the; same objection Avas found 

 to a])ply to solutions of quassiiji. The author arrived at thii 

 following niixtui'c as suita])le ffu- the luiipose and fiec from these 



ol)jections: — 



(jrms. 



ryrethiiim linctuie (20 Jiarts powdered i'yicthrum 

 flowers to 100 parts 96 per cent, spirits of wine, 

 to whicdi 21 per cent, denatured methyl alcohol 



lias been added) of this '^>H0 



Potash soap (as odourless as ])Ossible) ... ... 180 



Gly(;erin ••■ 240 



Tin- above mixture to be diluted with 20 volumes of water before 

 use. The apparatus used (-'} forms are figured) should have a 

 delivery tube of some length s(j that the operator shall not be 

 involved in the spray. The no/zle is directed to be held at 

 altout half a metre (18"-20") from tlie walls or objects to be 

 sprayed. In th(^ (^ase of operations lasting some time or under 

 conditions such that the operator can hardly avoid the spray him- 

 self, the use of a respirator is recommended. One hundx'd 

 'n-ammes of the fluid are said to suffice for 50 cubic metres. 



