DESTROYING INSECTS. 325 



ins-ects, whilst others, from what cause I know not, suffer Inquiry re- 

 severely. Unfortunately for myself I am one of t^se. ^^^^^^5 ^f ^j^^ 

 The bite of a common flea causes a very considerable degree stroyiBg fleas 

 of pain and inflammation ; so great indeed as totally to ^^^^^ 

 disturb my rest until either the little animal is satisfied, or 

 till I am fortunate enough to destroy it. If knowledge be 

 valuable in proportion to utility, the means of preventing 

 the distress occasioned by the bite of insects is not Jbeneath 

 the attention of philosophers. Cleanliness I know will 

 prevent the incroachment of these vermin; but no one can 

 guard himself from them by cleanliness of his own person, 

 unless he can prevail on all persons with whom he has inter- 

 course to take the same care. I wish some of your corre- 

 spondents who have pleasure in the study of natural history 

 would bestow some attention on this sujbject, and commu- 

 nicate to the public the result of their investigation. It is 

 remarkable that diflerent constitutions are so difierently 

 afiected by the same poisons. The bite of fleas or bugs is 

 insufferably painful to some pei'sons, whilst others are not 

 at all incommoded. The reason of this might be a subject 

 of curious enquiry, But it would be an important comfort 

 to those Avho suffer severely, to be acquainted with any 

 means of protecting themselves against such distress. The 

 common head-louse is easily destroyed or expelled from the 

 head by combing into the hair a small quantity of white 

 Hellibore. Whether this drug is equally deleterious to the 

 flea, I do not know, but the experiment might merit a trial. 

 Perhaps rinsing the blankets through an infusion or decoc- 

 tion of it, might render them a disagreeable lodgement to 

 any insect. Mercury we know is in every form destructive 

 to the insect tribe, but Avhether any useful application could 

 be made of it in this case I am unable to determine. I have 

 known the red nitrate of mercury combed into the heads of 

 children for the purpose of destroying vermin, and I believe 

 with complete effect. Many of the solutions of this mineral 

 are so corrosive as might injure the texture of the clothes; 

 but perhaps a very weak solution of the acetite of mercury, 

 Siippose a grain to a pint of water, might be used to rince 

 the clothes through, without injuring them, or occasioning 

 tp a person sleeping in them any unpleasant ©fifects j jet 



evea 



