Not Attainable by Effort 139
he may recognize and avoid the conditions that pro duce strain, and in some cases patients have obtained a complete cure in a very short time by this means alone. One advantage of the method is that it does not require a test card, for at any hour of the day or night, what ever the patient may be doing, he can always place him self in the conditions favorable to the perfect memory of a period.
The condition of mind in which a black period can be remembered cannot be attained by any sort of effort. The memory is not the cause of the relaxation, but must be preceded by it. It is obtained only during moments of relaxation, and retained only as long as the causes of strain are avoided; but how this is accomplished can not be fully explained, just as many other psychological phenomena cannot be explained. We only know that under certain conditions that might be called favorable a degree of relaxation sufficient for the memory of a black period is possible, and that, by persistently seek ing these conditions, the patient becomes able to increase the degree of the relaxation and prolong its duration, and finally becomes able to retain it under unfavorable conditions.
For most patients palming provides the most favor able conditions for the memory of black. When the strain to see is lessened by the exclusion of the light, the patient usually becomes able to remember a black object for a few seconds or longer, and this period of relaxation can be prolonged in one of two ways. Either the patient can open his eyes and look at a black object by central fixation at the distance at which it can be seen best, and at which the eyes are, therefore, most relaxed, or he can shift mentally from one black object to