g. Nausea.

h. Feelings of distance.

i. The taste of coffee.

j. An unrecognized smell.

k. The ringing in the ears that results from a large dose

p. The sight of a light by a four-weeks-old baby.

8. Show how the author of the following passage classifies sensations partly on the basis of felt likeness and partly on the basis of the sense organs concerned:

"Different Classes of Sensation.-Passing now to the enumeration and comparison of the different classes of sensation, we may begin with the following provisional list: Sensations of sight, of hearing, of contact and pressure; those due to the varying states of muscles, joints, and tendons as dependent on the position and movement of the limbs; sensations of smell, of taste, of temperature, and finally organic sensations. The last head requires some explanation. Under the term 'organic sensation' are included sensations due to the state of the internal organs of the body, such as headache, thirst, muscular cramp, or fatigue, nausea, etc." (G. F. Stout, Groundwork of Psychology, p. 42.)

9. Which groups in this classification most need further subdivision.

IO. What criticism may be made of a description of a group of feelings as "those due to the varying states of the muscles, joints and tendons as dependent on the position and movement of the limbs"?

II.

Criticise the following classification :

"Sensation.

and Special.

There are two classes of sensations,-General

General Sensations include all those which do not belong to the "five senses,"-those which constitute our bodily comfort or discomfort; they may be classed as follows:

Muscular Sensations of injury, fatigue, and repose.

Nervous Sensations arising from the state of the nervous system, as when we feel the exhilaration of perfect health or are weakened by care or suffering.

Vital Sensations, depending on the condition of the vital organs, as those of hunger and thirst and their opposites, the pain of indigestion, the feeling of suffocation when breathing impure air.

Special Sensations are of five kinds, namely, those of Touch (including those of the "Muscular Sense"), of Sight, of Hearing, of Taste, and of Smell."

12. No one has found a classification of smells that is either simple or comprehensive or scientific. It is interesting to try to classify the odors of the objects named below and compare the groups one makes with those made by others:

13. Give the names of two things which seem to you to have somewhat the same kind of a smell that the thing named has, in the case of each of the following:

14. Make a list of senses which it is conceivable that human beings might have, though they do not.

15. Which one of the senses provides the greatest variety of different qualities?

16. Which sensations are aroused by distant objects? 17. Which sensations are least delusive, most reliable? Experiment 1. Pressure Spots.-On the back of the hand, say between the base of the thumb and the base of the forefinger, mark off an area about an inch long and a half inch wide. Have ready: (1) a pyramid of cork about a quarter inch square at the base, about one quarter inch high and cut to a point, with a long needle or a tooth pick stuck into its base for a handle; (2) two

small metal rods, such as knitting needles, or pieces of wire with rounded ends, or better two hollow metal cylinders drawn to a closed point at one end.

Go over the surface of the skin with the point of the cork, touching each square millimeter lightly. Note the location of any spots where the touch of the cork arouses a much more pronounced feeling of pressure (of what is commonly called touch) than it does in general. Does the touch of the cork in some spots arouse a feeling of coolness? If so, locate these.

Experiment 2. Cold Spots.-Go over the surface of the skin with one of the rods cooled to say 50° Fahrenheit (if the hollow rods are used, they need only to be filled with cold water) and note the location of any spots where the touch arouses a much more pronounced feeling of coolness than it does in general. Touch these spots with the cork. What sensation results? Touch them with the second rod warmed slightly above the temperature of the room. What sensation results?

As an aid to remembering the location of the pressure spots and cold spots, it will be useful to draw on paper an enlarged outline of the area marked off on the hand, or to mark the hand itself with a tiny spot of ink or paint.

Experiment 3. The Threshold for Pressure.-Make 5 cylinders of wood about 4 millimeters in diameter and 1, 2, 4, 8, and 16 millimeters in height. Have each one smooth at top and bottom. Fasten to the center of the top of each by a bit of glue, a fine, flexible thread of silk. Tie the thread to one end of a small stick (tooth picks will serve), letting the length from the cylinder to the stick be about two inches. Holding the stick at the end removed from the thread, lower the cylinder gradually till it rests on some smooth surface, as a table-top. Each cylinder should, when thus lowered, have the plane of its bottom surface parallel with the table-top.

Let a friend be seated with eyes closed, fore-arm resting on a table, and the palm of the hand upward. Say to him: "I shall give as a signal the word ready. Then at the end of two seconds I shall either put a very light weight on your hand or I shall do nothing. If you feel a weight, say 'Yes,' if you do not feel any, say nothing." Then say, 'Ready,' and lower a cylinder gently till it rests on the center of the palm. Note the answer given, and remove the cylinder slowly. Record the answer. Repeat with another and so on through the following series: the 16mm. cyl

inder, the 8, o (that is, none at all), 16, 0, 2, 4, 2, 16, 0, 1, 8, 8, 2, 1, 4, 16, 1, 8, 1, 8, 1, 16, 2, 0, 1, 2, 0, 0, 2, 0, 16, 1, 1, 8, 0, 16, 16, 8, 2, 0, 0, 4, 4, 16, 0, 8, 8, 0, 16, 0, 4, 0, 2, 16, 0, 1, 1, 16, 1, 4, 2, 2, 8, 4, 0, 16, 4, 4, 4, 16, 16, 0, 0, 16.

Record the answers by drawing a line under the figure denoting the cylinder used if the subject answers yes, and a line through it if he says nothing. This method of scoring serves also to keep track of which cylinder is the next to be used.

Which weights are below the threshold? (Unless a cylinder was felt in eight cases out of ten it was probably not really sensed at all, for mere guessing would of course give fifty per cent. of correct answers.)

Try the same experiment placing the weights on the back of the wrist or fore-arm. Which weights are below the threshold here?

Experiment 4. The Mixture of Taste and Smell.-Arrange for a friend to give you a half hour of his time. Prepare 4 pieces (cubes about one quarter of an inch long) of each of the following: raw apple, raw onion, raw celery, cooked chicken, cooked beef, cooked lamb; and have ready a half spoonful each of honey, maple syrup, molasses, cinnamon, clove and nutmeg, a medicine dropper (a plain glass rod will do) and a salt spoon or a visiting card cut lengthwise into six or seven strips.

Let the subject of the experiment be seated, with eyes closed and nose carefully plugged with cotton. Say to him, "I shall put something in your mouth; taste it and tell me what it is before you swallow it." Require the subject to answer at once before the odor can penetrate to the nose through the passage at the back of the mouth cavity. Then place a piece or drop or pinch of the food, say a pinch of cinnamon, on his tongue and record his answer. Give the different substances in a mixed-up order, using each two times, and recording the substance and the answer in each case.

After these 24 trials have been made, remove the filling from the subject's nose and repeat the 24 trials.

Compare the number of errors in the two cases. Why would it be desirable to repeat the experiment on another person, testing him first with nose open and later with nose plugged?

References

A. James, Briefer Course, II. (9-16), III., IV., V., VI.

Stout, Manual, 117-124, 141-198.

Titchener, Outline, §§ 7-26.

B. Ebbinghaus, Grundzüge, §§ 13-36..

James, Principles, XVII. (1-9).

Wundt, Physiologische Psychologie, I., VII., VIII. (§ 1), IX.

§ 8. Percepts

The Nature and Attributes of Percepts. Our feelings of the world are commonly not of confused blurs and masses of colors, sounds, tastes, and the like, but of unified wholes which we call 'things.' We can in thought analyze our feelings of the outside world into elements of colors, sounds, pressures, etc., but in reality they appear as complex total feelings. The feeling of a 'thing' as actually present is called a Percept if the thing is actually present; an Illusion if it is not present but something else is which gives us the feeling; an Hallucination if nothing is actually present to cause the feeling. Thus my feeling of the page I see, the pen I hold, the chords being played on the piano or the puffing of the engine are percepts. My feeling as I lie dozing of a page seen, when really only a dirty blotter is seen, and of the puffing of an engine, when really only my own breathing is heard, are illusions. My feeling of music heard in a dream, when really no sound at all is audible, is an hallucination.

Feelings of things are most commonly based on sight and touch, less commonly on hearing, still less commonly on taste, smell or pain, and almost never on the feelings of nausea, dizziness, muscle-strain and other inner bodily conditions. We rarely say or think, 'I have a sourness,' or 'There are four dizzinesses in this room.'