M

= 43429 44819 03251 82765 11289 18916 60508 22943 97005 80366 65661 14453 78316 58646 49208 87077 47292 24949 33843 17483 18706 10674 47663 03733 64167 92871 58963 90656 92210 64662 81226 58521 27086 56867 03295 93370 86965 88266 88331 16360 77384 90514 28443 48666 76864 65860 85135 56148 21234 87653 43543 43573 17247 48049 05993 55353 05

where M denotes the modulus of common logarithms.

50

In these calculations the value of log

has been determined with

49

126
125'

less accuracy than that of log and therefore the value of log 7

found by means of the latter quantity has been preferred.

If now in the formula which gives Euler's constant we take n = 500, we find the following results:

R500=

00000 03333 33200 00025 39671 87309 34479 09501 49853 06920 81561 41982 03143 98353 10049 47690 35814 25947 82825 73530 80967 33251 23444 83365 27221 32891 79715 39888 78668 70158 11997 43277 84264 18919 84678 56672 58294 26067 37401 94207 08483 64907 04495 03811 66583 11699 18899 16275 81704 82573 08004 99446 91635

$500 6.79282 34299 90524 60298 92871 45367 97369 48198 13814 39677 91166 43088 89685 43566 23790 55049 24576 49403 73586 56039 17565 98584 37506 59282 23134 68847 97117 15030 24984 83148 07266 84437 10123 70203 14772 22094 00570 47964 42959 21001 09719 01932 14586 27077 01576 02007 28842 06850 09735 01135 74118 52998 6631

Loge 500 6 21460 80984 22191 74263 67422 42594 91605 47278 04331 52606 36739 79303 69340 93242 07062 36272 51021 28288 27237 62074 83901 87110 62880 60166 54305 61594 90289 71296 61913 55661 26910 65179 94054 14829 26073 41092 64585 48079 22114 05716 58115 31635 24264 74180 14925 98528 81625 94504 71489 68628 97329 77937 00975

E=

57721 56649 01532 86060 65120 90082 40243 10421 59335 93992 35988 05767 23488 48677 26777 66467 09369 47063 29174 67495 14631 44724 98070 82480 96050 40144 86542 83622 41739 97644 92353 62535 00333 74293 73377 37673 94279 25952 58247 09491 60087 35203 94816 56708 53233 15177 66115 28621 19950 15079 84793 74508 5697

Again, if in the same formula we take n = 1000, we find the following:

R1000

⚫00000 00833 33325 00000 39682 49801 59487 73237 84632 11743 88611 32124 18782 98862 06644 51967 06850 04241 14869 65631 43736 78499 44114 24665 37423 82138 50259 70190 89962 61572 33894 07843 88131 36054 55889 69002 08034 44545 27898 47738 31546 74821 27649 54293 18527 10148 88349 55931 43201 82238 86978 52223 81562

$1000 7.48547 08605 50344 91265 65182 04333 90017 65216 79169 70880 36657 73626 74995 76993 49165 20244 09599 34437 41184 50813 96798 01438 22544 03715 81484 21958 84703 40431 40398 43368 92966 39178 33827 35905 57913 00071 54692 68403 25933 79804 87809 56515 86955 67800 24804 71415 08712 32350 00711 42865 21027 95267 06455

Loge 1000 6.90775 52789 82137 05205 39743 64053 09262 28033 04465 88631 89280 99983 70290 27178 29032 05744 07079 91615 26879 48950 25903 35212 68587 45900 22857 63952 48420 26999 88621 07296 34506 84487 21624 97666 40425 31399 68447 86995 95585 18051 59268 96133 19788 65384 90098 66686 30946 59660 23963 10024 23212 72982 31056

E=

57721 56649 01532 86060 65120 90082 40243 10421 59335 93992 35988 05767 23488 48677 26777 66467 09369 47063 29174 67495 14631 44724 98070 82480 96050 40144 86542 83622 41739 97644 92353 62535 00333 74293 73377 37673 94279 25952 58247 09491 60087 35203 94816 56708 53233 15177 66115 28621 19950 15079 84793 74508 56961

It will be seen that the two values found for E agree to 263 places of decimals, which supplies another independent verification of the value obtained for log, 2.

February 14, 1878.

Sir JOSEPH HOOKER, K.C.S.I., President, in the Chair.

The Right Hon. William Henry Smith and the Right Hon. Sir William Henry Gregory, whose certificates had been suspended as required by the Statutes, were balloted for and elected Fellows of the Society.

The Presents received were laid on the table and thanks ordered for them.

I. " Concerning the Effects on the Heart of Alternate Stimulation of the Vagi." By ARTHUR GAMGEE, M.D., F.R.S., Brackenbury Professor of Physiology in Owens College, and JOHN PRIESTLEY, Assistant Lecturer in Physiology in Owens College. Received December 15, 1877.

In 1869, A. B. Meyer* observed that it was impossible to stop the heart in dogs and rabbits continuously by stimulation of the vagus

* A. B. Meyer "Das Hemmungsnervensystem des Herzens." (Abstract by Schiffer, "Centralblatt," 1869, No. 14, p. 216.)

nerve, even when the nerves were alternately stimulated so as to relieve one another.

In 1875, Tarchanoff and Puelma* stated, " Si l'on excite longtemps un des pneumogastriques du chien avec des courants forts jusqu'à épuiser complétement son action sur le cœur, ce qui se manifeste par le retour de ses battements et si l'on passe immédiatement à l'excitation de l'autre, on n'obtient plus d'arrêt du cœur, et même on n'observe aucune altération de son activité: et pourtant le nerf excité en dernier lieu n'est alors, on le conçoit, nullement épuisé." From this experiment they concluded, "que chacun des pneumogastriques met en jeu tout l'appareil modérateur situé dans les parois du cœur ; et qu'une fois cet appareil épuisé par l'excitation d'un pneumogastrique, il ne peut être mis en activité par l'excitation de l'autre."

In 1876, Tarchanofft published observations on the frog, in which he states that the behaviour of the frog's heart to vagus-stimulation is quite different, in respect of the mutual influence of the two nerves, from the behaviour of the heart of dogs or rabbits: "J'ai vu alors que si l'on attend pour exciter le second pneumogastrique que le premier ait été épuisé par l'excitation, l'arrêt du cœur s'obtient de la façon la plus nette;" and he concludes "Que chez les mammifères les deux nerfs aboutissent à un appareil modérateur commun, tandis que chez la grenouille chaque nerf aboutit à un appareil indépendant."

Between the publication of Tarchanoff and Puelma's note and the publication of Tarchanoff's later observations on the frog, the authors of this paper undertook to check Tarchanoff and Puelma's statement respecting mammals, and to extend the method of experiment to frogs. In the case of mammals, dogs and rabbits were used. They were rendered insensible by chloroform or ether, or subcutaneous injections of hydrochlorate of morphia. Their vagi were exposed in the neck and divided; and the peripheral ends loosely tied by ligatures. Arrangements were made to rapidly shunt an induced, interrupted current from a Du Bois-Reymond's induction coil, from one vagus into the other, the peripheral ends of the nerves being laid over fine platinum electrodes for the purpose. In all the experiments save one a Daniell cell was used to induce the currents. A cannula was placed in the femoral artery (in one case in the carotid artery) and connected with a kymograph, which wrote upon a moving sheet of paper.

In the case of frogs, the brain, and sometimes the spinal cord, were destroyed by pithing; a stout glass rod was thrust down the gullet;

* Jean Tarchanoff et G. Puelma, "Note sur l'effet de l'excitation alternative des deux pneumogastriques sur l'arrêt du cœur." "Archives de Physiologie," serie II, tome II, 1875.

M. de Tarchanoff, "Innervation de l'appareil modérateur du cœur chez la Grenouille." Marey's "Physiologie Expérimentale,” II Année, 1876, p. 289.

the vagi were exposed and placed each on a pair of fine platinum electrodes; and preparations were made for shunting an interrupted current, by means of a commutator, from one nerve into the other, just as in the case of mammals. Sometimes the heart was watched directly and notes made. At other times care was taken to register the heart's rate, the lapse of time and the moments of stimulation. The heart's rate was indicated by means of Marey's Myographe du cœur,* the time by an electromagnet and Ludwig's Unterbrechungsuhr, and the moments of stimulation by a marking key, each holding a pointed lever against a smoked revolving cylinder.

The general result of the experiments made by the authors of this paper, is the following: In all the animals hitherto examined (viz., dogs, rabbits and frogs), if one vagus be stimulated powerfully so as at first to arrest the heart, and if after the heart has recommenced to contract, the current be at once shunted to the other vagus, arrest again occurs in some cases, however, on again reversing to the vagus first stimulated, no effect is produced. This result may be formulated as follows: Stimulation of one vagus never annuls, or even prejudices, the inhibiting powers of the other vagus, unless when the inhibiting apparatus has been recently under stimulation for some time. It would therefore seem that Tarchanoff, in asserting the mutual prejudicial action of vagus-stimulations in mammals, and denying it in frogs, has missed one half of the truth in the case of the former, and the other half in the case of the latter.

In illustration of their statement of results of experiments, the authors append a reduced kymographic tracing of a dog. The animal was a young terrier, and the experiment was made in the manner above described. The arterial cannula leading to the kymograph was introduced into the femoral artery.

The upper line is the tracing of the kymograph, the middle line is the line of no pressure, and the lower line is divided into intervals of five seconds. The tracing reads from left to right. Quite at the left of the figure a small portion of the normal tracing is represented. At 2h. 25m. 15s., a stimulus was thrown into the left vagus, the secondary coil being 6 c.m. from the primary. At once the heart stopped and the blood-pressure fell. The heart recommenced, and at 2h. 25m. 32s. the current was shut off from the nerve. It remained off about 10 seconds, and at the expiration of that interval the current was thrown into the right vagus. Again the heart stopped, and remained motionless until 2h. 26m. 25s., a period of 43 seconds, the current, of course, passing the whole of the time. The heart then began to beat, and the blood-pressure rose towards the normal rapidly. At 2h. 26m. 53s. the current was shunted out of the right vagus into the left, the nerve first stimulated, and once more the pulse ceased and * See Marey's "Physiologie Expérimentale," II Année, 1876, p. 70.