results a little later when they had made a sufficient number of experiments to be worth while for use in obtaining valid conclusions.

EXPERIMENT. SERIES II.

An Attempt to Determine the Relative Value of Visual and Oral Instruction in Demonstration or Experi

mental Work in Elementary Biology.

Subjects: For this purpose two classes in the first term of the DeWitt Clinton High School were used. The classes had elected Spanish as their language. They were of poor average mentality, being rated as B classes by the elementary schools from which they came. Class 108 had 31 pupils, class 127 had 26 to 28 pupils present on the days when the experimental work was conducted.

Material Used: The classes were put through the test exercises during a succession of days during the first term at a time when the laboratory work was devoted to tests for food substances, the digestion of insoluble foods in growing seedlings, the work of the root in digestion and absorption of insoluble mineral salts.

Methods Used: In general the following was the method of procedure. The class was taught by the given method and allowed to make notes and write up as much of the experiment as possible at the time of the demonstration. The test examination was given during the first ten minutes of the period on the following day.

Description of Experimental Series.

First parallel experiment was made on February 26, 1917. Subject matter: To prove the presence of protein in an unknown substance. Class 108 was taught by the visual method. The day was clear; room 65°; humidity low. In making the test and the experiment which followed, the teacher carefully avoided all oral work. Names and scientific terms were written on the board and only such directions as were absolutely necessary were given. After performing the test (The Xanthroproteic) for protein, the teacher then tested the unknown substance for the presence of protein. Paper was given out at the beginning of the period, but before the experiment could be written up the bell rang for the close of the period. Boys were told to write up the experiment at home and bring it to school the next day.

Class 127 followed, the next period. The day was bright; temperature 68; humidity low. With this class the teacher developed the problem using the oral method of demonstration and in addition asked questions of nearly every member of the class in an attempt to make clear the steps of the experiment. Much interest was shown, the boys appearing to be active. The next day, at the beginning of the class period, the following question was given out: Problem: To test an unknown substance for protein. The day was bright, moderate winds, considerable humidity; temperature of 65°. Class 108 (visual method) appeared rather "stumped" when they got the dictated question. Some looked intelligent and got to work at once while several boys attempted to copy. Still others gazed in vacancy, only half the class worked with any degree of earnestness. Papers were collected after 7 minutes.

Class 127 on the other hand appeared to make a strong attack on the question. Two or three boys did not get to work, but in most cases mental activity seemed high. The time (7 minutes) was occupied by most of those at work.

Results.

A glance at the table shows a rather surprising equality, the average percentage of class 127 being 58.1%, while the average percentage of class 108 is 62.3%. This is contrary to expectations as the mental activity of class 127 certainly seemed greater. The question given was a pure memory question, and it would have seemed likely that either method would give results. The individual result showed an almost equal number of high marks by the visual and oral methods, but more absolute failures under the visual method. This, however, may be due to the mentality of the pupils, or it may be due to the faulty method used in allowing class 108 to take their papers home to finish.

The second of this test series was given after a lapse of several days. The same two classes were used, and the same order of test methods were used,-class 127 using the oral method, and class 108 the visual method. The type of experiment used was much harder to comprehend as it involved a series of three different pieces of work, all of which had to be connected logically in drawing the conclusion. The series first consisted of a test with phenolphthalein solution to show the color reaction caused by acid and basic substances. The test showed that acids bleached out the color from the solution. The next step was

to show two test tubes each containing a nearly neutral but slightly basic solution of phenolphthalein. In one of the tubes was placed a growing bean seedling, the acid from the roots. of which was sufficient after a few moments to change the color of the testing solution. The third step in the series was to show the effect of acid upon lime.

With class 127 which came after four periods of work, English, Spanish and two drawing periods, the experimental series was developed with an attempt to have the class formulate their own problems. The period was productive of mental activity on the part of the teacher and class, and the bell for the close of the recitation rang before the boys could copy the experiment.

Class 108 took the work after a program of Spanish, study, lunch. The above described experimental series was performed but so far as possible no oral work was done. The class observed the tests, and the experimental evidence, but no explanation was given and they were told to formulate their own problem. Most of the boys went to work with intense earnestness and worked quietly until after the bell rang for the close of the period. The class accomplished much more in actual laboratory work in the time given than did class 127, and at much less expense of energy to the teacher.

The following day, March 27, 1917, the test was given. The day was dry, clear and cool; room 68°, little humidity. Class 127 had previously studied Spanish, and had had lunch. The question given was the following: "Tell how the experiment with the phenolpthalein solution enables you to explain how the root takes in mineral material." A complete answer expected:

(1) Knowledge of fact that the "phenol" solution turned colorless in the presence of acid.

(2) That the roots give off an acid. (3) That acid dissolves limestone.

Class 108 followed, under same room and atmospheric conditions. Its previous classes were English, mathematics, study, Spanish. Both classes went to work earnestly and seemingly with intelligence. But the results which follow show that class 127 with the oral method understood the problem much better and gave a much better account of themselves in almost every respect. The average mark of class 127 oral was 6.6, while that of 108, visual, was only 3.9.

After this test was given, each of the above classes was given a third experimental lesson. On this occasion the methods

used with the classes were reversed, class 127 now being taught by the visual method and class 108 by the oral method. The lesson for this day was a simple experiment to determine the amount of loss by weight of organic matter and water in soil. In developing the problems with class 127 the fact was brought out that not only organic matter was burned out but that water was passed out in the form of vapor. The demonstration took nearly 20 minutes to work out, aside from the discussion because of the length of the time required to burn the organic matter out of the soil. The soil was weighed before and after heating; the figures in grams being placed on the board. The pupils were required to formulate their own problem but discussion over a proper title ensued.

With class 108 no problem was formulated but the steps of the experiment were carefully done and each student was required to pass up to the teacher's desk and make careful observation with eye and nose of the burning material over the bunsen flame, both before the organic matter and water had been eliminated and after it had been passed off. As previously the visual experiment was much more economical in time and energy of the teacher.

On March 28 test questions were given on this experiment and a fourth experiment series was made with class 127 again taking the visual and 108 the oral method of presentation. The following question on the previous day's experiment was given: "Suppose you were a farmer. Tell exactly how you would go to work to determine the amount of organic matter in the soil of your farm." To receive perfect mark, the boy had to show that he understood the experiment as well as to know that water and organic material were passed off during the heating of the materials.

Class 127 took this question at 3 p. m. after the following program: Drawing, (double period), lunch, mathematics, Spanish. The day was clear and cool, with rather high winds. It clouded over while the test was in progress, but soon cleared. The class at once went to work with seeming interest and determination. Class 108 followed the last period of the day after having had study, English, Spanish, mathematics, physical training. The room windows were opened, and a short settingup drill was given just prior to the test. The results of the question for the two classes follows on another page, class 127 receiving an average of 6.0, while class 108 received 6.2.

Following the test questions, the last of the series of experiments followed as has been mentioned above. This time an experiment was performed to show the relative power of different kinds of soil to hold water. Gravel, sand, poor soil, rich soil, and leaf mold were tested by pouring 100 cc. of water through 100 grams each of the different soils, noting the amount of water retained after ten minutes. The problem was, in each case, left for the class to formulate but the title of the experiment was discussed in the case of the class receiving oral instruction. In this test, as in previous tests, class 127 received visual instruction, and got over more ground than class 108, although in this experiment the time spent in writing up the experiment in the laboratory was more nearly equal than in any previous period.

On March 29 the following question was given to the two classes on this test: "Of what practical value to the farmer is the information gained from the experiment performed yesterday?"

Class 108 took the test early in the day after a gymnasium period. They were obviously a little boisterous, owing to the fact that they had been playing games, and did not settle down to the test at once. Class 127 took the test after a long program at the end of the school day. Their previous periods had been: Mathematics, English, lunch, Spanish, study. The windows were open prior to the test, and the class went through a settingup drill. The tabular results show a margin for the oral over the visual method of presentation in the laboratory. A graph made from the combined statistics of the four test series, making up the experiment, shows a decided advantage for the boys having the oral method of instruction in the laboratory. This is exactly what we would expect: two avenues of approach are better than one. Leadership makes for solution of problems; grouping about by individuals leads nowhere, especially if the individual is of too low mental ability, or if he is young and untaught in the methods of problem solving.

Conclusions.

Several general conclusions might be drawn from a sufficiently long series of experiments such as the writer has outlined. Such conclusions as have been put down here are, of course, merely tentative, and of little value as scientific conclusions. Still they are indicative of something.

1. The first noticeable feature of the series was that where