“Another experiment astonished me even more than this. We followed Pawlow down through a long narrow hall and upstairs into a room which was small and secluded, in a very quiet part of the laboratory, remote from any noisy occupation, and there we found a brown dog standing on a high table. It was a delicate and very intelligent looking animal. The attendant sat near by, and the dog was prepared as the other had been. As we came in, the Professor beckoned to us to sit down on a little bench beside the wall and indicated that we should be quiet. He stepped up to the dog, looked at him, and the dog recognized him with a smile in the dog’s way of smiling!—and presently the saliva began to flow. “Professor Pawlow was very much surprised. We had come into the room and he had offered the dog nothing, but the saliva was flowing. That was contrary to his expectation. He looked with considerable astonishment at the attendant. The attendant quietly said, ‘You have been feeding meat to the other dog, and he smells the meat on your hands.’ “The dog had such a keen sense of smell that the odor of meat on Pawlow’s hands even at a distance of several feet was sufficient to cause the saliva to flow. So he went out, washed his hands and came back. At this time, not a drop of saliva was flowing. The arrangement was such that every particle secreted must come outside of the mouth into these bottles. While we were waiting in silence, watching the dog quietly, suddenly the attendant pressed his foot without making any motion of the body at all, upon a little lever beneath his toe and the result was the causing of a high musical note to be sounded, a very high pitched tone. “Instantly, in less than three seconds, the saliva was flowing into the tube. We waited a little while until the saliva ceased to flow, then the note was sounded again. Instantly the saliva began to flow. “Professor Pawlow has been experimenting upon this line for a long time. Other experiments were made. One interesting experiment was with a large number of dogs. He had upon one counter a long row of dogs, about a dozen, which had their stomachs fixed in such a way, and their throats fixed also in such a way, that upon the secretion of the gastric juice in the stomach the juice would flow out into a flask.