REFLEX ACTION AND DISEASE. 645 



my own teeth by a headache in the temporal region. I had noticed 

 that during these headaches there was generally tenderness over the 

 aching part, and that there was also a tender point at some little dis- 

 tance, usually the eye, which was tender to pressure. On this particular 

 occasion, however, there was no tenderness of the eye, and I felt all 

 along the side of the cheek and under the jaw to see if I could dis- 

 cover a second tender spot. Under the ramus of the jaw I found a 

 small gland painful on pressure. As glandular irritation almost always 

 indicates something wrong in the lymphatics which pass to the gland, 

 I at once suspected something in the mouth to be the cause of the ten- 

 derness. As there was no abrasion or tenderness of the mucous mem- 

 brane of the mouth or tongue, I took a pointed instrument and tested 

 each tooth successively. At the very back of the crown of the last 

 molar I detected a small point which was tender upon pressure, and on 

 going to a dentist I was informed that the point was just beginning to 

 decay. Had it not been for the headache this would have passed 

 unnoticed, as the tooth itself had, up to that period, given me no 

 inconvenience whatever. Headache over the eyes, although frequently 

 depending on gastric irritation, is not unfrequently caused by straining 

 the eyes, and is only to be removed by lessening the work which these 

 useful organs have to perform. One finds this headache over the eyes 

 in men who work much with the microscope, or in women who are 

 engaged in fine needlework. Yesterday I met a case of this sort in the 

 surgery. This was a woman who had been accustomed to work about 

 her house, but who began to work at dressmaking three months ago ; 

 her hours of work being from 9 a. m. to 9 p. m., with an interval of an 

 hour for dinner in the middle of the daj'. About two months ago she 

 began to suffer from headache above her eyes, which makes her some- 

 times feel quite giddy. It gets worse in the evening about seven or 

 eight. The headache here, it will be observed, came on about a month 

 after the eyes had been subjected to this unaccustomed strain ; and it 

 became worse in the evening after the darkness rendered artificial light 

 necessary, and thus increased the visual strain. 



Ha^ang said so much on reflex action as a cause of disease, we will 

 now consider it as a method of cure ; and the first instance that sug- 

 gests itself to our minds is the beneficial effect of a blister. Two 

 theories have been proposed to account for the action of a blister. 

 One is, that it dilates the vessels of the skin in the part to which it is 

 applied, and, by thus drawing'away some of the blood from the inflamed 

 organ below, lessens the pain and inflammation in it. The other theory 

 is, that the blister acts reflexly upon the organ itself. The first of these 

 suppositions is very improbable, because the amount of blood in the 

 skin covered by a blister is exceedingly small, and, moreover, does not 

 come from the inflamed organ, with which the blistered piece of skin 

 may have little or no vascular action. The second theory is much the 

 more probable one, but it is not yet certain how the vessels of the 



