75 



early in June. When the water became stagnant through partial 

 draining, or by stopping of the pumps, A. quadrimaculatus was 

 apparently superseded entirely by species of Culex, though only an 

 occasional Cidex could be found when A. quadrimaculatus was abundant. 



SoLLMANN (T.). The Spreading Power of Coal Oils. — Jl. Amer. Med. 

 Assoc. y Chicago, 111., Ixxi, no. 19, 9th November 1918, p. 1553. 



The spreading power of oils on water is important in their use 

 against mosquito larvae. This depends largely on the presence 

 of aspbalt-like products which most crude oils contain in sufficient 

 quantity. Some, however, and especially refined oils, need the addi- 

 tion of asphalt. Kerosene requires about 0"1 per cent, of asphalt 

 varnish. If kerosene is dropped on a dish of water, it collects into 

 rather small plaques and spreads very slowly, if at all. If the asphalt 

 varnish has been added the kerosene spreads at once over the entire 

 surface of the water. 



Plotz (H.). The Importance of the Louse Problem. — Jl. Amer. Med. 

 Assoc, Chicago, III, Ixxii, no. 5, 1st February 1919, pp. 324-326, 

 2 figs. 



The fundamental principles of exterminating lice are reviewed, it 

 being pointed out that the virus contained in the excreta of the louse 

 must be destroyed as well as the insect and its eggs. Steam is accepted 

 as the best agent. The plan adopted against the introduction of 

 epidemic diseases by the U.S. Army in connection with demobilisation 

 is described and an account is given of a plant capable of freeing 

 260 soldiers and their equipment from lice in one hour. 



Mann (W. L.) & Ebert (E. C). Some suggested Improvements in 

 Methods of Petrolization of Mosquito-breeding Areas. — Military 

 Surgeon, Washington, D.C., xliii, no. 5, November 1918, pp. 543- 

 545, 3 figs. 



Oil-soaked sawdust appears to provide a satisfactory method of 

 securing an equal distribution of oil. The loose, dry sawdust is 

 soaked in oil for 24 hours and distributed on the surface of the mos- 

 quito-breeding areas by hand. Where the areas are inaccessible 

 owing to floatage and other conditions, the oiled sawdust may be 

 tied in paper bags and the bags thrown at random into the floatage. 

 To retard the flow of the sawdust down running streams a floating 

 boom should be placed across the stream at intervals of 50-100 feet. 

 These booms are made of beams, 1 foot by 2 feet and with a length 

 depending on the width of the stream. Both ends are anchored to 

 the shore with a cord allowing for the rise and fall of the water. The 

 boom should be in the form of an angle with the apex pointing down- 

 stream. In this angle the sawdust accumulates. A 1-inch gap in 

 the apex allows the sawdust to escape and it goes down to the next 

 boom where it is again retarded. 



As a substitute for oil-drippers the oil-soaked sawdust cage and 

 the automatic oil-bubbler are employed. In the case of the former, 

 the box should be placed in a stream so that only \-\ is submerged, 



