CUTANEOUS ANESTHETICS 243 



the finger to painful stimuli. Its undoubted value 

 in relieving toothache is due to its caustic action in 

 destroying irritated nerve-endings. The numb feel- 

 ing we get after prolonged soaking in i in 20 carbolic 

 is due to the formation of a thin coating of killed 

 epidermis over the hands. 



The fact that even cocaine, which is thoroughly 

 proved to paralyse sensory nerves, fails to produce 

 the slightest effect when a 10 per cent solution in 

 alcohol, or a 10 per cent ointment made with lanolin, 

 is rubbed into the skin, is strong evidence that little 

 if any of these alkaloids reaches the nerve-endings 

 at all. Atropine finds its way into the sweat ducts 

 sufficiently to reduce but not to aboHsh sweating 

 by its action on the sweat glands. It is true that 

 cases of poisoning from the application of belladonna 

 to the skin are recorded, but only where there were 

 abrasions or sores present, or perhaps in young 

 children whose skin is very delicate. 



It may be objected that there is sufficient clinical 

 evidence of benefit from these drugs to defy negative 

 results by experimental methods, but any who claim 

 this must not confuse the issue by combining the 

 belladonna or opium with camphor, heat, rest, or 

 strapping. Again, it may be suggested that atropine, 

 at least, has some vasomotor effect, but we failed 

 to observe any, and indeed we doubt if it ever reaches 

 the blood-vessels when rubbed into the unbroken skin. 



It is a thankless task to pull down strongholds of 

 belief, but it is necessary if only to direct more 

 attention to the true means of giving relief to pain, 

 including general drug treatment, rest, massage. 



