192 PHTHIRUS INGUINALIS. 



of rue, laurel, tobacco, and veratrum album, or the powder of any 

 of these substances mixed with lard, in the form of an ointment, 

 have been recommended as very effectual destroyers of the pediculi 

 of the head, and even of the body lice. Calomel, or the red oxide 

 of mercury mixed with starch powder, sprinkled amongst the hair, 

 or applied by means of a down puff, is equally efficacious. To 

 the phthirus inguinalis, or crab -louse, as to all other species 

 of insects, the mercurial oxides are the most fatal poisons. Two 

 or three applications of the strong mercurial ointment, assiduously 

 made, is usually sufficient to effect a cure. As its external use, 

 though very efficacious, is attended with much inconvenience from 

 the dirtiness of its application, other preparations of mercury are 

 frequently substituted. The most efficacious of these are the white 

 precipitated oxide of mercury, white hellebore ointment, and calo- 

 mel. The oil of spike, as it has been called, which is the essential 

 oil of lavender, mixed with oil of turpentine, has been deemed one 

 of the most efficacious poisons for these disgusting parasites. Sir 

 Edward Willmot is said, by Dr. Heberden, to have used, with 

 complete success, in a case of morbus pedicularis, a composition 

 somewhat similar to the spike oil, viz. of rectified oil of turpentine 

 and spirit of wine, each four ounces, camphor six drachms. Dr. 

 Bateman says, a solution of the muriate of mercury in spirit, is very 

 efficacious in the pedicular prurigo, and tends to remove the 

 pruriginous affection of the skin, which seems to give rise to the 

 tendency to generate lice. It is to be observed, however, that 

 none of these pungent stimulating substances can be applied to 

 the skin without inflicting extreme pain, unless the surface be 

 unbroken ; for where the cuticle is abraded by scratching, or other 

 causes, the irritation and smarting occasioned by them is intolera- 

 ble, and is followed by considerable inflammation. In many 

 cases, cleanliness itself is a sufficient remedy, and as the learned 

 Dr. Good shrewdly observes, " a sure prophylactic." 



