It is a well known fact that an operator can often control the pulse rate of his subject by some such suggestion as the following:

"Your pulse is beating very slowly. Feel it and notice how slow it is. Why, it is down to fifty; now it is forty, now it is thirty," etc.

This suggestion may be carried too far, even to the point of causing the heart to cease beating altogether, which would mean death. But this would be difficult to accomplish in most instances. Still it is well to bear in mind the possibility of such a suggestion.

Another improper suggestion to make, would be, "don't fall, or don't do so and so, for it will kill you." This might act as a post-hypnotic suggestion and prove disastrous should the subject ever meet with the accident mentioned. When a suggestion of inability is made, it should always be followed with a release, such as, "Now you can do it." This will often prevent unpleasant results, for hypnotic suggestions are capable of producing lasting impressions.

Similar precautions must be observed in suggesting irregularity of breathing. It is dangerous to suggest that the subject is suffocating and can't breathe. To do so may cause actual suffocation by allowing insufficient quantities of air to enter the lungs.