*Sore arm.
*Sore arm.
*Sore arm.
SLINEYPhotograph taken at the close of the experiment.
SLINEY
Photograph taken at the close of the experiment.
The main things in Dr. Anderson’s report especially to be emphasized are (1) the gain in self-reliance and courage of the men under training, indicative as they are of the better physical condition of their bodies, and (2) the marked increasein their strength as indicated by the steady improvement in the strength or dynamometer tests. Obviously, the daily training to which the men were subjected in the Gymnasium is not to be overlooked as one factor in bringing about the gain in accuracy and skill, and indeed this factor must count for something in explaining the general gain in bodily strength, but increased skill alone will not account for the great gain in muscular power.
The results of these systematic tests make it very evident that the men were not being weakened by the lowered intake of proteid food. On the contrary, their ability to do muscular work was greatly increased; a fact which cannot well be connected with anything other than the physiological economy which was being practised. There must be enough food to make good the daily waste of tissue, enough food to furnish the energy of muscular contraction, but any surplus over and above what is necessary to supply these needs is not only a waste, but may prove an incubus, retarding the smooth working of the machinery and detracting from the power of the muscular mechanism to do its best work.
The figures showing the total strength of the men in October, 1903, on their ordinary diet, and on the second day of April, 1904, when the experiment was nearing completion are certainly very impressive.
Here we see gains in strength of 100 per cent in some cases, while Coffman shows an improvement so marked as to be almost marvellous. While there can be no question that a certain amount of this gain is to be attributed to the practice incidental to these months of work in the Gymnasium, it is equally clear that a large part of the gain is due to the improved physical condition of the men’s bodies, for which the change in diet must be considered as responsible. In any event, the change from the ordinary diet to a diet comparatively poor in proteid has not resulted in any physical deterioration. On the contrary, there is every indication of a marked improvement in physical condition. In this connection the following note from Dr. DeWitt, commanding the detachment, is of interest:
332 Temple Street, New Haven, Conn.,March 30, 1904.ProfessorRussell H. Chittenden,Director Sheffield Scientific School,New Haven, Conn.Sir,—In compliance with your verbal request I have the honor to inform you that at this date the men of this detachment are all in good physical condition.Very respectfully,(Signed)Wallace Dewitt,1st Lieut. and Asst. Surgeon U. S. Army,Commdg. Det. H. C.
332 Temple Street, New Haven, Conn.,March 30, 1904.
ProfessorRussell H. Chittenden,Director Sheffield Scientific School,New Haven, Conn.
Sir,—In compliance with your verbal request I have the honor to inform you that at this date the men of this detachment are all in good physical condition.
Very respectfully,
(Signed)Wallace Dewitt,1st Lieut. and Asst. Surgeon U. S. Army,Commdg. Det. H. C.
Finally, attention may be called to the photographs of the men, taken just prior to the close of the experiment, from which may be gained some idea of their physical condition so far as it can be judged by external appearance. Certainly, there is no indication in these photographs of any lack of bodily vigor. On the contrary, there is good muscular development, without any undue amount of fat, and indeed every indication of a good bodily condition, coupled with that appearance of quickness and alertness that belongs to the well-developed man, in a state of physiological balance. Thephotographs scattered through this section of the book, showing the soldiers at work in the gymnasium, likewise give some idea of the lighter forms of exercise they followed each day in the training of bodily movements.
What now is to be said regarding the nervous condition of the men;i. e., their ability to respond to stimulation or, in other words, their mental quickness or reaction time? To study this question, the soldiers were sent with regularity to the Yale Psychological Laboratory, where their reaction time was studied with great care. The results of this investigation are contained in the following report made by Dr. Charles H. Judd, in charge of the Yale Psychological Laboratory.
REPORT ON REACTION TIME.In order to test the quickness of the members of the Hospital Corps Detachment, and to determine whether the changes in diet affected in any way their ability to respond promptly to sensory stimulation, each man was carried through a series of reaction experiments at the Yale Psychological Laboratory. The method of the experiments was that regularly employed in simple reaction time experiments. The person whose reaction time is to be measured is seated in a comfortable position with his finger pressing on an electric key. He is told that he is to lift his finger from the key as quickly as possible when he hears a given sound-signal. The sounder which produces this signal and the electric key are placed in a circuit with a standard time-measuring apparatus—the Hipp Chronoscope. This chronoscope is arranged so that it begins to record the instant the sound is given and stops the instant the reactor lifts his finger. The dial of the chronoscope shows in thousandths of a second (hereafter designated by the technical termsigmas) the time that elapses between the sound to which the reactor is to respond and the movement of response. The chronoscope was tested at frequent intervals by means of a standard pendulum and errors in the record are well under two sigmas.The time which is measured by this method is occupied chiefly by nervous processes. The following factors may be specified:First, the auditory organ is aroused by the sound; second, the afferent nerve transmits the stimulation to the central nervous system; third, the central nervous system carries the energy to the motor nerves; fourth, the efferent motor nerves transmit the stimulus to the muscles; and finally, some time is required by the muscle for its contraction. It will be seen, accordingly, that the chief factors of a reaction are nervous processes, and since the external conditions of successive reactions are in all respects uniform, any variations in the time of a given person’s reactions may be regarded as indicating variations in the nervous condition of the reactor. In view of the instability of nervous conditions, it is necessary to eliminate any slight or merely temporary fluctuations by taking each time a given reactor is tested a series of reactions. For this reason, a series of ten reactions was taken with each of the men every two weeks during November, December, and January. After an interval of two months, namely, on March 30, 31, and April 1, two final series were made with each man.The results are presented in tables 1 to 5. The dates in the first column indicate the day on which each individual set of ten reactions was taken. The second column presents the averages of each ten reactions in sigmas. The third column gives the mean variations of the various single reaction times from the average. The fourth column gives the variations of the day’s average, recorded in column 2, from the general average of that individual for all his experiments. These general averages are presented in table 6. At the bottom of each complete column of averages will be found the group average. This quantity is obtained by averaging the results from all the members of the squad for periods of, approximately, two weeks.The mean variations in the third column make it clear that the subjects did not settle down into what could be regarded as trained subjects. Trained subjects are expected to give mean variations which are consistently within the limits of 10 per cent of the average. While there are, of course, instances in which the mean variation falls within this limit, there is no consistent exhibition of the regularity indicative of thorough practice. This fact is further confirmed by a comparison of the results of March 30, 31, and April 1 with those of the earlier months. At the end of March, all effects of practice in November, December, and January,except the most general, may be regarded as having disappeared; and yet the averages and variations for the March and April dates resemble closely those of the month immediately preceding and also those of November. The effects of practice may, accordingly, be regarded as insignificant.This lack of special training accounts for the large variations which appear in some cases. As is usual in reaction experiments, the signal to which the reactors were to respond was in each case preceded by about two seconds by a bell signal to arouse attention. Conditions were thus rendered as nearly uniform as possible, but the variations indicate in three or four cases exceptional lapses of attention. Such exceptional cases can be eliminated without prejudicing the final validity of the results by substituting the median for the averages. In table 7, the medians are grouped together and show even more than the tables of average the absence of any general variation during the period of the tests.The obvious conclusion from these tests is that the quickness of the members of the squad underwent no general change during the whole period covered by the test. Individual members showed variations from time to time, but these variations are clearly accidental in character, for they show no regular tendencies and are in no way related to the changes in the character and amount of the diet.(Signed)Charles H. Judd.April 12, 1904.
In order to test the quickness of the members of the Hospital Corps Detachment, and to determine whether the changes in diet affected in any way their ability to respond promptly to sensory stimulation, each man was carried through a series of reaction experiments at the Yale Psychological Laboratory. The method of the experiments was that regularly employed in simple reaction time experiments. The person whose reaction time is to be measured is seated in a comfortable position with his finger pressing on an electric key. He is told that he is to lift his finger from the key as quickly as possible when he hears a given sound-signal. The sounder which produces this signal and the electric key are placed in a circuit with a standard time-measuring apparatus—the Hipp Chronoscope. This chronoscope is arranged so that it begins to record the instant the sound is given and stops the instant the reactor lifts his finger. The dial of the chronoscope shows in thousandths of a second (hereafter designated by the technical termsigmas) the time that elapses between the sound to which the reactor is to respond and the movement of response. The chronoscope was tested at frequent intervals by means of a standard pendulum and errors in the record are well under two sigmas.
The time which is measured by this method is occupied chiefly by nervous processes. The following factors may be specified:First, the auditory organ is aroused by the sound; second, the afferent nerve transmits the stimulation to the central nervous system; third, the central nervous system carries the energy to the motor nerves; fourth, the efferent motor nerves transmit the stimulus to the muscles; and finally, some time is required by the muscle for its contraction. It will be seen, accordingly, that the chief factors of a reaction are nervous processes, and since the external conditions of successive reactions are in all respects uniform, any variations in the time of a given person’s reactions may be regarded as indicating variations in the nervous condition of the reactor. In view of the instability of nervous conditions, it is necessary to eliminate any slight or merely temporary fluctuations by taking each time a given reactor is tested a series of reactions. For this reason, a series of ten reactions was taken with each of the men every two weeks during November, December, and January. After an interval of two months, namely, on March 30, 31, and April 1, two final series were made with each man.
The results are presented in tables 1 to 5. The dates in the first column indicate the day on which each individual set of ten reactions was taken. The second column presents the averages of each ten reactions in sigmas. The third column gives the mean variations of the various single reaction times from the average. The fourth column gives the variations of the day’s average, recorded in column 2, from the general average of that individual for all his experiments. These general averages are presented in table 6. At the bottom of each complete column of averages will be found the group average. This quantity is obtained by averaging the results from all the members of the squad for periods of, approximately, two weeks.
The mean variations in the third column make it clear that the subjects did not settle down into what could be regarded as trained subjects. Trained subjects are expected to give mean variations which are consistently within the limits of 10 per cent of the average. While there are, of course, instances in which the mean variation falls within this limit, there is no consistent exhibition of the regularity indicative of thorough practice. This fact is further confirmed by a comparison of the results of March 30, 31, and April 1 with those of the earlier months. At the end of March, all effects of practice in November, December, and January,except the most general, may be regarded as having disappeared; and yet the averages and variations for the March and April dates resemble closely those of the month immediately preceding and also those of November. The effects of practice may, accordingly, be regarded as insignificant.
This lack of special training accounts for the large variations which appear in some cases. As is usual in reaction experiments, the signal to which the reactors were to respond was in each case preceded by about two seconds by a bell signal to arouse attention. Conditions were thus rendered as nearly uniform as possible, but the variations indicate in three or four cases exceptional lapses of attention. Such exceptional cases can be eliminated without prejudicing the final validity of the results by substituting the median for the averages. In table 7, the medians are grouped together and show even more than the tables of average the absence of any general variation during the period of the tests.
The obvious conclusion from these tests is that the quickness of the members of the squad underwent no general change during the whole period covered by the test. Individual members showed variations from time to time, but these variations are clearly accidental in character, for they show no regular tendencies and are in no way related to the changes in the character and amount of the diet.
(Signed)Charles H. Judd.
April 12, 1904.
The following tables give all the data upon which the foregoing conclusions are based, being furnished by Dr. Judd and Mr. Warren M. Steele, Assistant in Psychology, by whom the observations were made. Dr. Cloyd N. McAllister, Instructor in Psychology, was also associated in the making of these observations.
One question that naturally arises in considering the possible effects of a diminished proteid intake upon bodily health is whether a continued diminution of proteid food will have any influence upon the character and composition of the blood. It might be claimed, for example, that a lowering of the quantity of proteid food below the ordinarily accepted standards will eventually result in a deterioration in the character of the blood. Obviously, if such should prove to be the case, it would at once emphasize the necessity for higher standards of proteid feeding. Further, there might result marked changes in the hæmoglobin-content of the blood in connection with a lowered proteid metabolism long continued. With these thoughts in mind, a careful study of the blood of the soldiers has been made from time to time, with special reference to determining the number of erythrocytes and leucocytes in the fluid, attention also being paid to the percentage of hæmoglobin.
Four distinct observations were made, as a rule, upon each man, namely, in the months of October, December, January, and March. The results are tabulated in the accompanying tables. Examination of these results shows that, as a rule, the number of erythrocytes, or red blood corpuscles, was somewhat increased during this period of lowered proteid feeding. We are not disposed, however, to lay very much stress upon this apparent increase, because it is not sufficiently marked to carry much weight, especially in view of the difficulties attending the obtaining of great accuracy in blood counts in general. Regarding the leucocytes, the figures are less definite, but may be fairly interpreted as indicating practically no appreciable change in the number of white corpuscles. Similarly, the hæmoglobin-content shows no distinct alteration. Hence, the conclusion is that the physiological economy practised by the soldiers during their six months’ stay in New Haven, and especially the marked diminution in the amount of proteid food consumed, did not result in any deterioration of the blood, so far as it can be measured by the number of contained erythrocytes and leucocytes, and by the content of hæmoglobin.
Careful consideration of the foregoing data, taken in their entirety, must lead the unbiassed thinker to admit the possibilities of physiological economy in nutrition. That there is no real need for a daily diet containing 118 grams of proteid food seems clearly indicated. The members of the soldier detachment lived without discomfort for a period of five months on amounts of proteid food not more than one-half that calledfor by the ordinary standard dietaries, and this without increasing the amount of non-nitrogenous food. Body-weight, nitrogen equilibrium, physical strength and vigor, ability to respond to sensory stimulation, the composition and general condition of the blood, all remained unimpaired under a daily diet involving the metabolism of only 7 to 8 grams of nitrogen per day and with a fuel value of less than 2800 calories per day.