of the pain, but it is often difficult to demonstrate tenderness; for notoriously the most painful disturbances take the form of anginal attacks, in which condition the patient is not in a fit state to give an account of himself. Sometimes, as is well known, the pain radiates down the ulnar side of the arm to the wrist or little finger, and sometimes it starts from this and radiates up to the chest. In diseases of the heart, and more especially in aortic disease, the pain is referred along the first, second, third, and fourth dorsal areas. In angina pectoris the pain may be referred in addition along the fifth, sixth, seventh, and even the eighth and ninth dorsal areas, and is always accompanied by pain over certain cervical areas.

In diseases of the lungs the areas corresponding to the second, third, fourth, and fifth dorsal segments are most commonly affected, and apical phthisis frequently gives pain and a sore feeling over the third dorsal spine and spine of scapula.

Stricture of the esophagus affords one of the most definite instances of referred pain, for there the pain can be produced by swallowing. Generally the pain is referred to a point about two inches from the middle line exactly at the angle of the scapula, and associated with pain in front over the fifth interspace about one-half inch internal to the nipple line. There is sometimes pain and tenderness in the back over the fifth, sixth and seventh vertebral spines.

Pain in gastric disturbances is almost always accompanied by some cutaneous tenderness. This tenderness lies in front between the level of the ensiform cartilage and the umbilicus. It occupies one or more of the three areas corresponding to the supply of the seventh, eighth or ninth dorsal segments. One of the most common situations for pain is at the epigastrium, just over the ensiform cartilage, and this is one of the maximum points of tenderness of the seventh dorsal area. In cases of gastric ulcer cutaneous tenderness is nearly always present over this area and over a point in the line of the angle of scapula at a level of the ninth dorsal spine.

The eighth dorsal area seldom appears alone in affections of the stomach, but nearly always with the seventh and ninth

areas. Its characteristic tender spot is situated over the eighth space, almost exactly in the midaxillary line.

The area corresponding to the ninth dorsal root is one of the commonest of all the stomach areas. It appears repeatedly in cases of gastric ulcer. All areas associated with the stomach tend to appear bilaterly. The seventh dorsal area seems particularly to appear in anything which causes vomiting, and when it appears as a sequel to vomiting it is frequently accompanied by the area corresponding to the sixth dorsal. Now, the sixth dorsal is associated with disease in the lower part of the aesophagus, and hence it seems reasonable to say that when both areas are present the disease is near the cardiac orifice. In the same way the ninth dorsal area is shared by both the stomach and intestines, and thus a lesion of the stomach causing pain over this area is probably situated near the pyloric orifice.

In cases of gastralgia and gastric ulcer, in which the pain bears a definite relation to the ingestion of food, and where the seventh dorsal segment is affected and the maximum tenderness is situated at and around the ensiform cartilage, the pain comes on within half an hour after the food is swallowed. On the other hand, in cases where the ninth dorsal segment only is affected, the pain does not come on until the food has been swallowed at least an hour. This again favors the view that the seventh dorsal segment supplies the cardiac end of the stomach, while the ninth dorsal supplies the pyloric end.

And conversely, each portion of the skin periphery is associated through the nerve centres which supply it with nerve filaments, with some special visceral periphery or vascular area; and whatever effect is produced upon the vascular area of the skin is likewise produced in the internal vascular area associated with it.

In 1874 Schuller published the results of a remarkable series of experiments made upon trephined rabbits in which he demonstrated the effects upon the internal circulation of thermic and mechanical applications to the surface, cold causing contraction and heat causing dilatation. Vinaja, in 1892, reported experiments upon a man whose brain had been exposed

by an accident, which confirmed the observations of Schuller respecting the influence upon the brain and circulation of thermic applications to the skin in various parts and under various temperatures.

Brown, Sequard, Winternitz, Tholozan, Rusback, Nauman, Priesnitz, and many others have demonstrated the reflex effect of external stimuli on the viscera, and confirm the reflex topographical areas of Head, MacKenzie and Dana. And within the last few years a valuable series of experiments has been carried on in the Battle Creek Sanitarium, under the direction of Dr. Kellogg, clearly showing the influence of thermic applications upon the amount, temperature, pressure, and cellular constituents of the blood.

Experiments showing influence of the proximal compress upon the temperature of distal parts:

Experiment I.-Subject was a young man, aged 23 years; temperature of hand, 90.5 degrees; elbow immersed in bath at 50 degrees. After two minutes temperature of hand was 87 degrees. Twenty minutes after removal of arm from the bath the temperature was still below the normal.

Experiment II.-Initial temperature in axilla, 99.8 degrees; palmer surface of hand closed, 98.1 degrees. The elbow was immersed in water at 42 degrees for thirty minutes, at the end of which time the axillary temperature was 100.8 degrees, and the hand temperature, 96.1 degrees.

Experiment III.-The subject was a young woman just convalescing from typhoid fever. The blood pressure, as determined from the middle finger of each hand by Gaertner's tonometer indicated a pressure of 7 cm. mercury. The two hands were immersed, the right hand in ice water, the left hand in hot water for five minutes, at the end of which time the tension was found to be, for the right hand 5.5 cm.; for the left hand 9 cm., a difference of 3.5 cm.

The same experiment made in healthy subjects showed a difference of about 1 cm. of mercury.

This experiment very clearly shows the influence of cold in contraction of the surface vessels, and heat in dilating the vessels and exciting the surface circulation.

Experiment IV.-Showing effec's of very hot applications in producing an initial slowing of the pulse with subsequent increase.

Subject was a young man. The normal radial pulse rate was found to be 70. The arterial tension, as indicated by Gaertner's tonometer, was 9 cm. The subject was placed in an immersion bath at 102 degrees. The pulse immediately fell to 61. At the end of fifteen minutes the pulse rate was 87, and the tonometer registered 6 cm., showing a marked fall in blood pressure.

By a comparison with the preceding experiment, it will be seen that local hot applications produce a rise in blood pressure, while general hot applications produce a fall. Thirty minutes. after the bath the pulse rate was 60, and the tonometer reading 8 cm.

Experiment V.-Showing influence upon the general temperature and circulation of the ice bag placed over the heart.

Subject was a young man, with a normal pulse of 80; arterial tension, 10 cm.; mouth temperature, 99 degrees; subject placed in a reclining position, and an ice bag placed over the heart. After three minutes, pulse, 72; arterial tension, 12 cm. At end of one hour, mouth temperature, 98.5 degrees; rectal temperature lowered I degree.

Experiment VI.—Showing rate of time of impulses under different conditions.

Rate of time required for the patient to make a signal after an impression was made upon the finger, II-100 seconds. After the elbow of the same arm had been packed in ice for five minutes, the time required was 22-100 seconds.

Experiment VII.-Showing the reflex effects of the cold compress. An ice compress applied to the abdomen and sacrum reduced the rectal temperature from 99.8 degrees to 98.6 degrees in thirty minutes.

Experiment VIII.-An ice compress to the abdomen and sacrum, combined with a hot foot bath, reduced the rectal temperature from 99.8 degrees to 97.4 degrees in one hour and ten minutes.

A few minutes' reflection will show the possibilities of the

simultaneous applications of cold and heat, the former over the area in sympathetic relation with the diseased part or organ, and heat over a part which is closely associated in relation to its blood supply.

Evperiment IX.—Subject was a young man aged 26 years; axillary temperature was 97.7 degrees, mouth temperature, 97.7 degrees; rectal temperature, 99.2 degrees; surface temperature at epigastrium, 97 degrees. The patient drank in rapid succession seven glasses of lemonade at 58 degrees. A fall in the axillary temperature was noted in five minutes. At the end of twenty minutes the axillary temperature was 96.1 degrees; mouth temperature, 98 degrees; rectal temperature, 98 degrees; surface temperature of epigastrium, 92 degees.

Experiment X.-Showing local increase in blood count from cold applications. Short, hot, abdominal formentation was followed by a snow compress for twenty minutes. Blood count before the applications gave 4,450,000 red blood corpuscles, 49 white blood corpuscles, and 96 per cent. hemoglobin; after the application, the count showed 4,950,000 red blood corpuscles, 10,100 white blood corpuscles, and 99 per cent. hemoglobin. Examination fifteen minutes later showed the blood count to be practically the same as before the applications.

Thayer, of Johns Hopkins Hospital, found that the blood drawn from the lobe of the ear of a typhoid patient, after the Brand bath, contained three times the number of leukocytes, ascertained by actual count to be present previous to the bath; and this has been confirmed by Winternitz, Breitenbach, Baruch, and others in chronic cases and in healthy persons.

But besides the reflex effect, there is a mechanical effect which is commonly the reverse of the reflex. The real effect of the irritant is the sum of these two effects, and depends upon the relative intensity of the two actions. The duration of the reflex effect depends upon the intensity of the stimu-. lant and also upon the area involved. When the cutaneous vessels of a large portion of the body are excited in contraction by thermic applications, the contraction of the interior vessels is brief. It may even escape notice. The reason for this is the development of the mechanical effect from the large