PHYSIOLOGICAL June 14, 1924.

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1 PROCEEDI NGS OF THE PHYSIOLOGICAL June 14, SOCIETY, Two simple break keys. By S. L. MUCKLOW and B. A. MCSWINEY. The following two keys were designed with the primary object of providing a "Break" key which would be simple to make, would withstand regular use by students, and which would be interchangeable with the existing key on a Palmer drum. Key 1. This consists of an ebonite block on which a light brass arm A is mounted so that it pivots about the screw C. In the "On" position the arm A makes contact with the stud B. Both A and B are connected 7/6 A to terminals on the ebonite block. A short rod D projects at right angles from the arm A and this rod is struck by the revolving arm on the drum and operates the key. The rod E is merely for convenience in operation. This key has been found very suitable where a slow moving drum is being used. Key 2. The second key was designed so that the contact would be unaffected by vibration, and is suitable for use with a fast-moving drum.

PROCEEDINGS OF THE PHYS. SOC., JUNE 14, 1924. xi A brass arm A is mounted horizontally on an ebonite block so that it pivots about the screw C.

2 PROCEEDINGS OF THE PHYS. SOC., JUNE 14, xi A brass arm A is mounted horizontally on an ebonite block so that it pivots about the screw C. One end of the arm A is fashioned into a cam which bears against a light watch spring F. In the "On" position the arm A makes contact with the stud B. Both A and B are connected to terminals on top of the key. The rod E is provided for convenience in operation. The key is operated by the revolving arm on the drum striking the arm A. It will be noticed that this key provides positive "On" and "Off" positions. We are indebted to Mr F. S. Wilson, of the Physiological Department, Manchester University, for making up these keys to our designs. Inexpensive long paper kymograph for student's use. By WALTER J. DILLING. The advantage of students in practical classes of a long paper kymograph is often apparent but the cost of providing such equipment is usually prohibitive. The simple arrangement indicated in the diagram is serviceable for both slow and fast speeds provided the paper travels horizontally. An ordinary stand, clamped to the bench, has adjusted on it a brass side arm with vertical steel rod. On the rod of the stand is placed a flanged bobbin of the width of the paper and on the rod of the side arm an unflanged bobbin to place tension on the paper and provide a flat writing surface between the two bobbins. A narrow flange on the lower rim of the driving drum prevents slipping from variation of paper tension. The cost of side arm for stand and of bobbins should not exceed five shillings.

3 xii PROCEEDINGS OF THE PHYSIOLOGICAL AdJustable lever and pulley for experimental work. By WALTER J. DILLING. The instrument shown in the scale drawing has proved very useful for student's purposes and has withstood serious damage. The essential feature is the division of the brass rod support into two parts by a friction-tight ball and socket joint. This renders possible the rapid and fine adjustment of the wheel in any direction and saves shifting of the boss-head. The grooved wheel and lever arm are made of aluminium-somewhat stouter than is drawn. The lever arm is fixed to the side of the wheel by a pin with socket and a detachable screw-or it may be run into a tight groove-so that the arm may be removed and the wheel used as a guide pulley. The provision of a small strip of steel (watch) spring rivetted to the lever arm enables the thread passed over the wheel to be caught quickly and firmly in the angle between the spring and the lever arm; when the length of thread is finally adjusted, a half clove hitch can be made in the angle leaving a loop from which weights can be hung and the loop made secure by a second hitch. The point of the lever arm may be modified for vertical writing, if desired. The lever is particularly useful for work with surviving mammalian tissues, since adjustment of tho vertical position of the tracing can be made from the ball and socket joint. When used as a guide pulley the practicability of placing the wheel at any angle and in any position has advantages. The cost of such a lever should not exceed 30s.

-SOCIETY, JUNE 14, 1924. xiii Pituitary extract and fatty infiltration of the liver. (Preliminary Communication.) By R. COOPE and E. N. CHAMBERLAIN.

4 -SOCIETY, JUNE 14, xiii Pituitary extract and fatty infiltration of the liver. (Preliminary Communication.) By R. COOPE and E. N. CHAMBERLAIN. In a series of 10 rabbits, fed on a diet of oats, bran and green vegetables, subcutaneous injection of 3 or 4 c.c. of commercial extract of posterior lobe of pituitary gland resulted in definite infiltration of the liver with fat. We have not yet ascertained precisely how soon the increase begins, nor when it passes off-in the three cases where the animal was killed 15 to 18 hours after the injection, the total fatty acid in the liver was 8l35, 7*25 and 6-49 grams p.c. of the fresh tissue, as compared with an average of 2-97 p.c. for 7 controls. The work is being continued and extended to other mammals. The CO-dissociation curve of haemochromogen. By M. L. ANSON and A. E. MIRSKY. We have determined the carbon monoxide dissociation curve of haemochromogen prepared by alkaline hydrolysis of ox blood diluted twenty times. None of the impurities were removed. The curve can be expressed by the mass law equation K-[He] [CO] [He CO]- The value of K at body temperature, in very alkaline solution is when the tension is measured in p.c. of an atmosphere. The percentage saturation was determined by analyses of the gas phase before and after saturation. We are studying the influence of various factors on this reaction. The acid base equilibrium in muscle. By S. ANDREWS, FLORENCE BEATTIE and T. H. MILROY. The constituents of muscle which carry base in a form which can be secured by acids produced within the fibres are bicarbonates, alkaline protein salts and phosphates. As regards the bicarbonates the concentration is a very low one, even in the absolutely fresh muscle (frog) not amounting to more than molar (Meyerhof). In the expressed juice of mammalian muscle the only base-carrying systems of importance are the phosphates and the proteins. As regards the phosphates the concentration in the freshly-expressed cooled juice is much higher than the bicarbonate, varying in different

2[1V PROCEEDINGS OF THE PHYSIOLOGICAL mammalian muscle from about 0-015 to 0030 molar.

5 2[1V PROCEEDINGS OF THE PHYSIOLOGICAL mammalian muscle from about to 0030 molar. In the warmed muscle juice the free phosphate concentration is increased to a variable extent, but approximately 0x015 mol. Not only does the phosphoric acid increase under such conditions but along with the acid change and the resultant alteration in the dibasic. ratio there is also usually a monobasic slight increase in the total base carried by the phosphate system. The phosphoric acid therefore which is set free from its inorganic forerunners secures base from some other system. At the same time there is produced by the warming an increase in the lactic acid, and between the reaction of the cold and that of the warmed juice this acid procures practically its full supply of base, and from some system other than the phosphate one. The evidence regarding the base derivable from the protein system is based upon experiments of the following type. The phosphoric acid, lactic acid and reaction were determined in the expressed juice of fresh mammalian muscle before and after warming. Thus the increase in these two acids was determined between the two reaction points. At each reaction the approximate dibasic-monobasie phosphate ratio was calculated, and knowing the absolute H3PO4 concentration the amount of base held at the outset and after warming could be calculated. In the same way, knowing the amount of lactic acid formed, and recognising that this acid, even at the more acid reaction, was practically entirely in the form of lactate, the base value of the lactic acid increment was arrived at. An example may be given of an experiment with the expressed juice of horse muscle before and after warming. HaPO4 dibaic mol Mllimols ph (molar) monobasic of base held Cooled juice 6*77 0*026 * * Warmed juice 6*18 0* *0337 In passing from the cooled to the warmed juice there was an increase of 0034 mol. lactic acid per litre, corresponding approximately to 34 millimols base, so that the total base increment in millimols per litre was approximately 44. In order to arrive at further information regarding the source of this base, the ultra-filtrates of cooled and warmed specimens of the juice were examined and the results obtained show that the proteins constitute an important source of the base secured during acid production in muscular tissue. The main buffers, the principal

6 SOCIETY, JUNE 14, base carriers, are the phosphate and the protein systems, but the former alone does not furnish the supply of the base secured by the lactic acid. It is evident that during acid production in muscle the energy changes associated with the process must be largely due to the part played by the proteins in their transformation from the ionised to the undissociated state. The relation between the size of the electrical response and the tension developed in the contraction of striated muscle. By C. F. WATTS. The electric response and the contraction of skeletal muscle are known to vary in a similar way in magnitude with varying stimuli, but their exact relation has not been established. Experiments have XV therefore been made to ascertain whether a quantitative relation could be established between the size of the electrical disturbance and the tension developed in an isometric contraction. The muscle used was the sartorius of the frog. A monophasic response was recorded by killing the tibial end of the muscle, which was stimulated directly at the

xvi PROCEEDINGS OF THE PHYSIOLOGICAL pelvic end. The tension lever used had a magnification of 15-5 times, and was photographed simultaneously with the galvanometer string.

7 xvi PROCEEDINGS OF THE PHYSIOLOGICAL pelvic end. The tension lever used had a magnification of 15-5 times, and was photographed simultaneously with the galvanometer string. Stimulation was by break induction shocks, varied in intensity by altering a resistance in the primary of the coil. The results show that the electrical disturbance and the tension developed increase in parallel manner as the stimulus is made stronger. This is shown in the figure in which the electrical response is plotted as p.c. of the maximum P.D. developed and the tension in grams also as a p.c. of the maximum. It will be seen that the ratio of the size of the electric response to the grams tension developed remains practically constant. According to the work of Lucas(l) and Pratt(2), the strength of the contraction increases, within limits, with the stimulus because the number of fibres in action increases and not because of any change in the response of each fibre. This suggests that variations in the magnitude of the electric response of the muscle are due to similar causes. This view is supported by Gotch's (3) work on the time relations of the response in nerve and by the observations of Adrian(4) on muscle stimulated with a Pratt electrode. If this view is correct, we must suppose that when only a few fibres are excited the inactive fibres act as a short-circuiting path for some of the current from the active fibres. When all, or nearly all, the fibres in the muscle are contracting, however, the number of short-circuiting fibres is so reduced that the resistance of this path for the current is greatly increased and more current flows through the galvanometer. By assuming that the resistance of an active and an inactive fibre are approximately equal, it is possible to calculate the current that flows through the galvanometer when different numbers of fibres are excited. Let G = conductivity of the galvanometer. X =,,,, active fibres. Y,,,, inactive fibres.,, e = E.M.F. produced by each fibre. The conductivity of the whole circuit is:- 1 X (G + Y) 1 1 G+X+ Y X G+ Y The current through the galvanometer = e.x(g+y) G C _= G+X+Y *G+Y G+NX'

8 SOCIETY, JUNE 14, XVll1 when X + Y = N. Thus the current should be directly proportional to the number of active fibres. If the mechanical tension developed is also proportional to the number of active fibres the ratio of the size of the electric response to the grams tension developed ought to remain constant, as it is found to do experimentally. (1) Keith Lucas. This Joumr 33, p (2) Pratt. Amer. Journ. Physiol. 43, p. 159; and 44, p (3) Gotch. This Journ. 28, p (4) Adrian. Arch. Neerlandaises, 7, p Relation between speed and efficiency (continued). By F. A. DUFFIELD and J. S. MACDONALD. Continuing the work previously reported(l), another subject, "J. McHugh" (age 20, weight 79*5 kilos, height 6 ft.), has been examined cycling at different rates and with various values of the brake. The "brake" range being from 0 to 1-9 kals. per minute, that is to say, from 0 to about 0*18 "horse-power," and the "revolution rate" from 40 to 20 Ca X 1.0 lo ~~~~~~0,~ l Metabolism in Kals. p.m. Heavy lines J. McHugh. Dotted lines... Harrison. 30/5/ per minute. The results are represented by the heavy lines in the accompanying chart. Attention is drawn to the fact that these lines are straight, are almost parallel(2), but that they are not equidistant as in the case of Harrison. These results therefore cannot be expressed so simply as in that case, where the statement Q = OK + qv was obviously admissible. Some more complex statement must therefore be found to unite the two cases. b

xviii PROCEEDINGS OF THE PHYSIOLOGICAL. On the same chart in "dotted lines" the previous results with "Harrison" are plotted out so as to render comparison possible.

9 xviii PROCEEDINGS OF THE PHYSIOLOGICAL. On the same chart in "dotted lines" the previous results with "Harrison" are plotted out so as to render comparison possible. The main difference is the very marked displacement of the heavier subject's lines along the abscissa. There is a marked payment for increase in weight. The "cost of movement" that is the distance from the origin to the feet of the sloping lines varies with W01.44 of the subject's "stripped weight," and with a still greater power of the subject's unmodified weight(3). There is therefore no possibility whatever of stating the "cost of movement" as equal to xw I + ywv2 as two fractions representing the basal metabolism and a cost for "velocity." There is, however, also another very important distinction between the two cases. "Harrison's" lines (dotted lines) make a definite angle with "McHugh's" lines (heavy lines). Now with regard to the slope of these lines it is in the first place clear that if they were vertical then there would be no "cost of work," and that the more they slope the less this is true, therefore the more erect lines of the heavier subject show definitely a greater efficiency associated with a greater weight. The variation as in the direct calorimetric experiments is such that the "efficiency" varies directly with WOH. With regard to the meaning of this variation which might be read as either the "disefficiency coefficiei4" E = a constant. a constant surface weight x height' Equations have been made with the data published in 1916(2) in the form log E _ x + y log WO + z log H so as to discuss this meaning and their result is as follows: KH surface x W* So that the "efficiency," which is the reciprocal of E varies with the surface of the body, and with the ratio between the cube root of the mass of the body (muscularity) and the height. Returning to the cost of movement and the mentioned impossibility of stating it either as r,v, or as xw01 + ywv2, attempts have been made to express the two sets of results in various ways, the best of which seems to be the following: xw01 The total cost + ywv2 + EK. + (H'0) The first of these three fractions represents the "basal metabolism" as

10 SOCIETY, JUNTE 14, being diminished with increasing rate of movement, which indeed is very probably the case, and it, at the same time, serves to express the great variation, already alluded to, in the "cost of movement" of subjects of different weights. REFERENCES. (1) F. A. Duffield and J. G. Macdonald. Proc. Phys. Soc. 58. Dec. 15, (2) Capt. M. Greenwood. Proc. Roy. Soc. B (3) J. S. Macdonald. Proc. Roy. Soc. B XiX The relation between "basal metabolism" and "cost of movement." By J. S. MACDONALD. The total cost of cycling, given in "Kals" per minute, of the two subjects now very completely examined is expressible, as follows, in three fractions (WO is the weight of the unclothed subject) 0*138W0l 5.77WV K Q= 9290V VK Added together, the two first fractions represent the cost of movement; the last fraction represents the cost of work. In the last fraction K is the load, or " brake power " in " Kals " per minute and the figure by which it is multiplied is the constant " disefficiency coefficient," which varies inversely with W1, and therefore whether essentially, or for some secondary reason, inversely with the surface of the body. The greater the surface the less the cost of work. The first fraction is notable as having an existence when there is neither external work " K," nor movement " V," since when " V," the revolution rate per minute, is naught, the fraction becomes 0-138WO, and may then be styled the " basal metabolism" for the cycling posture, that is " B." Its value then is larger than the " resting metabolism," since equivalent, in a subject of ordinary weight, to 67 kals per hour per square meter of surface. When movement begins, this fraction is reduced since the denominator then enlarges. The reduction is represented as a very substantial one, the fraction being halved at 45 revs. per minute, and brought down to a third of its value at 90 revs. per minute. Now this denominator, expressed in " c.g.s." units may be shown in the following two forms: (1)1+ S Ee (1) 1+{(2T) 5 B} 10-b013 n2 b 2

11 xx PROCEEDINGS OF THE PHYSIOLOGICAL e12 in which E and B have the same meaning as above, (2)5 represents a number of calories, and seconds, as a time factor, eliminates the influence of " n," the number of " strides per second " (double the number of revs. per second). Treated in this way the denominator represents a "pure number," which is of importance. (2) 1 + 2'r { (2 (76O n, wo in which "6" is a constant of the value , or V10Ire; and the exponent 3*116 may be written in the form 2 (1 + loge 472). This second mode of expression can only be considered as that of a pure number if (7r0)3 can be referred to as a " mass." Now as to the real significance of this constant " 0 " some very definite connection with thermal " quantities " may be inferred from the fact that the "mechanical equivalence" of heat may be stated thus: 1 calorie = ergs = 27T -- 6) g ergs. 27T2 If in this expression -6 i.e. *9810, may be taken as a "length," and its cube as a mass, the calorie is arranged as if work was done in lifting a mass, through a distance, against gravity. The distance, *9810, is interesting because as a matter of fact 6 = LOTO where L. and Lo are the latent heats of ice and water, and To and T8, the freezing and boiling points on the "absolute scale," namely, 273 and 373 ; and thus the magnitude of the path is proportional to the ratio between the two extreme states of water, or to a " power" of that ratio. Taking the 2e calories from the first of these forms 27T5 calories = 2 x 27r g ergs = (6)'g ergs, a fact which shows the relation between the two forms. Two other points might be alluded to with regard to the value of "6." Thus l, = 27r62: and again if the time taken by one calorie in traversing one cubic centimeter along a temperature gradient of one degree = t, then 7r2t = 64. A further point is to distinguish this " length " from the interesting " time " 10'968 seconds, during which a body would fall to such

12 SOCIETY, JUNE 14, xxi a distance as would require a " calorie " of work to replace it, this " time," 62, is equal to -2 In conclusion attention is drawn to the need for inserting a "dis-,efficiency coefficient," such as E. in the first two fractions as well as in the last one. Such an insertion would convert xwo0 into EyWOH, and in the second fraction zwv2, into ExWV2 x as is probably required by the fact that the mainresistance to movement is the " windresistance."

6I2.74I.63:6I2.8I7. averaging in one table only 65 p.c. and being rather variable. The

6I2.74I.63:6I2.8I7. averaging in one table only 65 p.c. and being rather variable. The 6I2.74I.63:6I2.8I7 THE IDENTITY OF THE RESPONSE OF MUSCLE TO DIRECT AND INDIRECT STIMULATION. BY W. HARTREE. (From the Physiological Laboratory, Cambridge.) IT is commonly objected to myothermic observations