644 THE POPULAR SCIENCE MONTHLY. 



minuria was produced bj the application of a dressing to an anal fistula, 

 which ceased when the dressing was removed, and again appeared on 

 its reapplication. In this case the vessels of the kidney seem to have 

 been reflexlj affected by the irritation applied to the anal nerves to 

 such an extent as to produce albuminuria, although probably no organic 

 disease of the kidneys themselves was present. Exposure of the 

 abdominal walls to rapid changes in temperature may bring on 

 diarrhoea, as the natives of India well know. It is possible that in 

 these instances the cold acts through the abdominal walls upon the 

 intestines themselves ; but it seems also highly probable that some part 

 at least of the action is reflex from the surface of the abdomen. What- 

 ever the cause of it may be, however, it may be guarded against by 

 wearing a cummerhwid, like the Hindoos ; and it is well for persons 

 who are subject to diarrhoea to wear, even in this country, a warm 

 woolen or silken belt around the abdomen. 



Irritation in the intestines may induce, not merely vomiting and 

 diarrhoea, but even general convulsions ; and cases are on record of 

 epileptic fits having been produced by the presence of a tapeworm in 

 the intestine, which ceased upon the expulsion of the intruder. Hys- 

 terical fits, although their pathology is far from being understood, are 

 now becoming to some extent associated with ovarian irritation ; for it 

 is found that, in many cases of hysteria, the ovaries are tender upon 

 pressvire, and that the hysterical fit may frequently be instantaneously 

 arrested by pressing upon the ovaries. 



We have so far been dealing chiefly with reflex action as a cause of 

 disease, but now we must say a word or two respecting the transfer- 

 ence of impressions. It is well known that persons who have had their 

 legs amputated often complain of cold feet, or of pains in their toes, on 

 change of weather. The irritation here is really in the end of the 

 divided nerve in the stump. But the brain is accustomed to refer all 

 impressions made upon a nerve during its course to the terminal 

 filaments from which impressions usually come, just as we feel a tingling 

 in the fingers when we pull upon or jar the ulnar nerve, or, as it is 

 popularly termed, the funny-bone. In disease of the hip, the irritation 

 is felt, not so much in the hip itself, as in the knee. 



In headaches one can frequently trace the origin of the pain to 

 some point at a distance from the aching part. Some years ago I met 

 with a case which was to me very instructive. A woman complained 

 of a headache situated in the left temple. One of her teeth at the 

 same time ached somewhat, and I gave her a pledget of cotton-wool, 

 dipped in solid carbolic acid, to put into the cavity. To my disappoint- 

 ment it had little or no efi'ect ; but five minutes afterward, on the 

 removal of the cotton-wool to the cavity of a second tooth, likewise 

 decayed, but which had not at first been suspected as the cause of the 

 mischief, the pain disappeared entirely from the temple. Some time 

 afterward I was led to discover an unsuspected decayed spot in one of 



