OTAGO INSTITUTE

Otago Daily Times, Issue 16120, 8 July 1914, Page 9

OTAGO INSTITUTE

.MONTHLY MEETING. SEVERAL PAPERS. ', Tho monthly meeting of the Otago In* , stituto was held last night, Dr Malcolm px£ siding over a good, attendance. HOW A MUSCLE WORKS. Dr Malcolm delivered an address oqt "How a Muscle works." Muscle, he eaid, was simply meat. Each muscle was a distinct organ, enclosed in a inembrane and attached to a l particular point. By a contraction of a muscle the movable point wae caused to move, and that was how bodily motion was brought about. The speaker produced legs of a Irog,. cut from the animal 20 minutes before, and used them as a basis of his experiment. Every muscular contraction, he 'said, wae caused by a nervietimulus, emanating from a brain cell. 'I* life, these stimuli were produced in tHtf ordinary way. But after death the mueole . . could ■» caused to contract by such '*' \ stimulus ae an electrical current. >■' Dr Malcolm produced an elaborate, jre* easily understood, piece of apparatus. The muscle of the frog was stretched betweeW two conducting wires, and attached to o*»> of the wires was an index, by which '46y contraction or relaxation of the musclar - could be registered. He" then sent an eleo' trie current through the muscle, and tho oscillation of the index showed a contraction, and subsequent relaxation had taken place. The oscillation of the index was «Sr. creased by it 6 motion over a sphere covered with lamp black, upon which it traced » pattern corresponding to its movement Tho speaker showed how, by comparison with the ascertained vibration of a tuning fork similarly traced on the sphere, the amount of time occupied by the contraction could he measured. He also showed the work ot< tho muscle in lifting a, suitable weight, when' operated upon by an electrical stimulus, and illustrated the failure of the fatigued muscle to respond. Compound or sustained musonlar contrao* tione were attributed by Dr Malcohn to a discontinuous series of nervous impulses, and the name given to them, he said, wae tetanus. He graphically illustrated the action in this case by means of his carboncovered sphere. ». DUNEDIN WEATHER. *

Mr D. Tannock asserted that Dunedia weather was not the worst in Now Zea- • land, as is so often said. He claimed a, very good oliraate for the city, and quoted figures in support of hie contention. For the 12 months ended March 31, he said, June was the driest month, with 91 point* of rain. The instruments at the observatory*' of course, could measure 1-100 of an laci*;and so a day officially described as "wet" might bo marked by a very small rainfall.' The wettest month wae August, with a rain*. fall of 771 points. The total rainfall w«fc 42 inches 26 points, and the number of , days on which rain fell was 170. October* was warmer than November, though tlii* should not, in the ordinary course of events, have been the case. In October, rain fe» on 16 days, and in November on 19 dayfc For the • different centres the mean tens' perature in the shade tor the 12 months was 6b degrees in Auckland, 53.2 degreee m. Wellington, 51.8 degrees in Chrietehureiv 51.1 degrftes m Dunediii, and 50 degrees u£ invercargilJ. Xhe mean maximum tempeAturcs were as follows: —Auckland, 6W degrees; Wellington, 61.1 degrees; Chnefr ' church, 60.6 degrees; Dunedin, 53 degrees;* Invercargill, 5tf.2 degreee. The mean* minimum temperatures were:—Auckland, SUM degrees; Wellington, 50.1 degrees; (JSnnetv, church, 43 degrees; Dunedin, 44.2 degrees; Invercargill, t<5.2 degreee. It was, the speaker tsaid, the mean minimum tempera- ,, ture at *vnich a plant was able to live that determined whetner or not it was hardyVIt wae found in Dunedin that, owing to tbß , high minimum temperature, gardeners werif able to grow a considerable number or plante that could not be grown in the otiier centres. The speaker had had no, difficulty in growing the North Island native plants, and .had grown the Nikau palm, ior instance, in the open air. tieverting to tigurce, he said tnat, in Aupk- h land during tne year with which he wM/ dealing, 3V.04 inches fell on 131 daye; fa. Wellington, 49.29 inches fell 0n!213 dayfli.j in Chnetchurch, 25.12 inches fell on Wo days; in Dunedin, 42.26 inches fell on 17Q, days; and, in Invercargill, 48.82 moke* fell on 213 days. Chrietchurcb had tbff' lowest rainfall, Auckland the second lowoet, and Dunedin the third, seven inches lew than Wellington. - ■ Dunedin was second lowest with regard to the number of daye on which rain tell. "We have, therefore," tho speaker concluded, " comparatively pleasant weather in Dunedin." Dr Marshall remarked that in four years out of every five, it would be found thai tho hottest day in Dunedin was hotter than; tho Ihottest day in Aiickland, though Auckland hi»d more hot daye in the aggregate. OTHEB PAPEES. Mr G. Howes showed & number 'of aluminium caste of flowers and leaves, and described them interestingly.

Professor Benham delivered an interesting addre&s on the native and other rats, aud described the origin of the English r*ty and its introduction into New Zealand. ■£!*, also laid on the table papers on the Oligojchaeta and the littoral Polychaeta, from the Kermadecs. ■ «.. ■•■•.!' Dr Benham announced that in September: a meeting would 'be held of a branch, of the British Association for the Advance- * ment of Science. A certain number of. scientists would bo the guests of the d<* r minion. They would be at Auckland, and would hold scientific meetings at Wellington and Christchurch. It wae hoped . that some of them would come to Dunedin,'. and deliver popular lectures, and that Dun;,' edinites would be able to welcome them., Papers on scientific subjects would be reacf; at the meetings.in the north, and persona' wiehing to have their papers read should communicate with tbo secretaries of the various sections upon which papers 'would be acceptable.

The next meeting- of the institute will be on August 4. '