SCIENCE SIFTINGS.

Auckland Star, Volume XLIV, Issue 34, 8 February 1913, Page 15

SCIENCE SIFTINGS.

VOLCANIC DL'ST IN ATMOSPHERE. From many poiiite in America and Europe come reports of an unusual turbidity of the atmosphere, whicih began early last summer n-nd still continues. This is manifested in a marked diminuitiou of the intensity of solar radiation, as measured with the pyrheliometer, ab normal displacement of the neutral points of atmospheric polarisation, a hazy appta.ra.nce of the sky, and the presence of Bishop's ring around tihe sun. From Dubdin Sir John Moore wrote last August:—" The t-ky is constantly covered with a thin film of uniform cloud in which no b olios develop, and through which the sun, moon, and stars shine wit,!] a subdued, sickly brightness." Observers in llur*»ia, Switzerland, Sweden, and Germany, as well as America, report an unusual lack of blueness in the sky. There seems to be every reason to attribute these phenomena to tbe preeen.ee in t-he upper atmcfsphcrc of an irameru-e pall of duet arising from the explosive eruption of Katmai volcano, in Alaska, last June. Similar effects were observed after the eruptions of Krakatoa and Monte Pele, and in those cases ttie phenomena lasted for some years. ELECTRICITY AS AN AID TO SLEEP. Electric sleep is to be the great boon of nen-e-dieordered humanity >f the expectations of Dr. F. Nagetecinnldt, of the Berlin Kiiieen Institute, axe realised. Some years ago (says Sif-tinge") Dr- produced sleep in animals by applying continuous electric currente on the base oS the brain, but the currente ne-uctisary were near the danger point, and .the claim of Dr. NageLschniidt is an improved method, ueing a special alter noting current giving narcotic effects without exceeding, or even nearly approaching, the limit of safety. It appears that not only can the number of voile, milliamperes, and alternations be fixed 03 needed, but that the time the cuTTPnt will How can be predetermined as well. Uiroonscioueness is produced cjuivkiy, awakening follows in a minute or two after the current ceases, and the alternating current not only relieves insomnia, but it hae other useful etteste, speedily overcoming neuralgic pains, and giving particularly a harmltes meane of uoatroiling the violent insane wiLhout the stout-jacket. The electric sleep can be deepened so ac to give painiess execution of criminate or slaughtering of animals. A DEADLY DISEASE. It was recently reported that Dr. Yorkc. of the Tropical School of Medicine, was advocating the extermination of big game in Rhodesia in order to stamp out sleeping sickness. It may be added that sleeping sickness has of "late years been increasing at an alarming rate amongst the natives of certain parts of Africa. Five or six years aco 40.000 or 50.000 natives of Uganda and over 500,000 of the Congo were reported to have died of the disease. That white men were immune from it was long believed, prcbaoly ibecause very few of them frequented the countries where the disaese raged, but the death of Lieutenant Tulloch, ILA.M.C, who contracted the disease while experimenting at the laboratory in Uganda, and succumJbed to it, completely disproved that idea. It is a deadly disease, that makes few and very slight exceptions. It was formerly considered virtually impossible to drive the disease out when once lodged. It has been claimed, however, that an antimony compound has I the remarkable effect of cleansing the ■blood of the organisms of infection, whilst the injection of an ana line preparation has also been successfnl in some cases. In the course of correspondeTiee a year or two ago between the British Government and the Governments of the African protectorates, the suggestion was raised that the common tsetse fly might prove to be a carrier of sleeping sickness, and it was snggested that this fly might be eliminated by the destruction of game. The Colonial Office decided to carry out such an inquiry I for a period of three years at a coet not exceeding £5.000 a yaar. A Commission (of which Sir David Bruce. F.R.S., was chairman ,and which was appointed under the joint auspices of the British Government and the Royal Society) reported in June last that it had proved that the tsetse fly, known ac glossina morsitans, as well as the glossina palpalis, was a carrier of the disease. Significance vss attached td the fact that while tbe glossina palpalLe frequented a limited region, the tsetse fly was widespread, and therefore difficult to exterminate. UNRELIABILITY OF TESTTMCTNT OF Unreiiaibflity of the testimony of eyewitnesses, ■which bae often been 'eJfitten of, was recently put to an amusing pi*ctical test by an American professor. In order to test the memory and susceptibility to suggestion of hds pupils he performed the folhrwing experiment on 48 boys between the ages of 14 and 17. He parsed a silver coin around 'tie clasa, instructing each 'boy to examine it carefully, but giving no further indication as 'to the punpose of his action. At tihe end of the lesson, which in other respects proceeded as usual, the profeeeo-r. having again taken possession oif the coin, addressed the class ac follows: — " You have no doubt observed that the coin which I handed around had a hole in it; nqw I should like to test your powers of observation. I am, ibhexefore, going to aek each of you to indicate the point on the coin where the bole is iound. Just take a piece of paper, draw a circle upon it. and indicate roughly the position of the head on the coin and of the hole wliich you observed." As a matter of fact there was no ■hole in the coin at all. Nevertheless, no ferwer than 44 out of the 48 pupils indicated the position of the alleged hole in tite coin, aome even indicating the position of two holes. Of the four remaining pupils, only one positively aeseTted fthat there wae no hole in the coin; the other tlhree merely said that they had not observed the bole. This alone is interesting enough, but there were seve.ra3 other features in the case which are well worth recording. In the first place, the one and only individual who had not been open tT> suggestion was a boy who had previout~3y shown his independence by giving considerable difficulty in mattere of discipline. Furthermore, several of the younger boys, even aft-s: they were toid that there was no hole in the coin, absolutely refused to admit this. The " Scientific American," eommeniting upon this experiment, remarks:—"lt 'hardly needs to be pointed out 'how significant an observation of this character is in its 'bearing on legal testimony. We must not be surprised that tie witness may, under certain circumstances, not merely make a certain statement incompatible ■with facts, but may even insist in his crrorieo-js belief in the face of overwhelming evidence against it—and aIJ this in perfectly good faith."