416 MEDICAL ENTOMOLOGY 



a number of small boxes rather than a few cumbersome ones. The floor 

 of the box is prepared as follows ; cork mat, preferably the prepared kind, 

 is cut up so as to fit the floor of the box. A quantity of paraffin wax is 

 then melted and to it is added napthaline in the proportion of one to four. 

 A thin layer of this is then poured on to the floor of the box, and the 

 cork pressed into it till it sets. More paraffin and napthaline mixture 

 is then poured on to fill up all the crevices and to form a layer a quarter 

 of an inch deep over the cork. The wax should be very hot when added 

 and the box held flat till it has set. Any air bubbles which form may 

 be removed with a hot knife. The boxes so prepared keep out all 

 destructive insects, including ants. A plug of cotton wool on which 

 is placed a few drops of essence of mustard is pinned in one of the 

 corners ; this helps to keep the box free of moulds in the rainy season 

 in the tropics. A small bag filled with crystals of carbolic acid should 

 be pinned in another corner, for it also helps to prevent the growth of 

 moulds. In moist climates it is useful to have a small tube containing 

 some anhydrous calcium chloride firmly secured in another corner of the 

 box ; when the calcium delequeses it should be renewed. The lid of the 

 box may be fastened in position by a small clip or by an elastic band. 

 The boxes are easily stored in a rack or small cabinet, the contents 

 being indicated by a label on one side. 



As a further precaution against injurious insects a few drops of the 

 following fluid placed on some cotton wool in the corner of the box will be 

 found useful. 



Saturated solution of napthaline in chloroform . . . ten parts. 



Creosote six parts. 



This fluid should never be used in large quantities, nor should it be 

 allowed to come in contact with the body of a fly ; it almost immediately 

 turns it black. 



In damp climates the following method for preserving delicate blood- 

 sucking Diptera, such as mosquitoes, Phlebotomtis, Culicoides, etc., is 

 recommended. The fly is mounted on a card or cork disc in the usual 

 way, and the pin supporting the cork is passed into the inner side of the 

 cork of a small specimen tube instead of into the collecting box. A small 

 wedge-shaped piece is cut out of the cork to allow of communication with 

 the external air ; the whole tube with its contained specimen is placed 

 in a dessicator. The tin box used for drying cigars, with a compartment 

 at the bottom separated from the rest of the tin by wire gauze and 

 containing anhydrous chloride of calcium, serves the purpose quite 

 well. The tubes are placed in the dessicator for three or four days ; 



