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once diminish the accuracy of H.'s answers. On one occasion, R.'s servant entered our workroom in the middle of an almost perfect series of answers: they at once became less accurate—

6 cm.	1	2 R.	3 W.
	2	5 W.

After his withdrawal H. again began to answer as before—

6 cm.	1	9 R.	1 W.
	2	9 R.	1 W.

Any profound cooling of the skin, or even the occurrence of a pilomotor reflex, greatly diminishes the accuracy of the answers to compass stimulation. When the coat is removed, and the sleeve is rolled up, "goose-skin" is frequently produced; testing should not be begun until this has entirely passed away.

We always began a series of tests with the compass-points widely separated from one another (9 cm.). Not uncommonly the records considerably improved as the distance was gradually diminished, and were frequently better at 7 cm. than at 9 cm.

This well-known phenomenon seemed, in H.'s case, to be associated with the increasing detachment of his attention from the procedure of testing. The following series of records obtained from the abnormal area on the left forearm are a good instance of such improvement.

6 cm.	1	9 R.	1 W.
	2	9 R.	1 W.

The improvement at 4 cm. was associated with complete wandering of attention from the manipulations. When at the close R. asked whether there was anything to say about these observations, H. could have quite believed that nothing had been done. He was thinking about a book he had been reading and was completely absorbed, until recalled by R.'s question.

Occasionally, especially after exercise in the open air, this condition of detachment would pass into sleep. We noticed that the answers seemed to improve up to the point at which H. ceased to reply and therefore made several observations on the effect of somnolence on the compass-records. On October 26, 1907, H. fell asleep at the close of the following record—

6 cm.	1	5 R.	5 W.
	2	10 R.

5 cm.	1	5 R.	5 W.
	2	6 R.	4 W.

4 cm.	1	9 R.	1 W.
	2	9 R.	1 W.

an unusually good formula for the affected forearm. He was wakened and after a short interval it was found that the same distance of 4 cm.