SCIENCE NOTES.

Otago Witness, Issue 2883, 23 June 1909, Page 84

SCIENCE NOTES.

— Tests for Drinking Water. —

If a sample of water contains much Organic- matter, living or dead, it may be (dangerous. There are several simple tests ipx organic matter in water. Twenty grams or nearly two tablespoonfule of a fconcentrated solution of tannin may ue fodd>2d tc a glassful of water. If the water •becomes tui^bid in lass than an hour it shotild- be rejected. Another test is the addition of a few drops of a i to 1000 solution of potassium permanganate to a glass of water, and the pink tint produced should not disappear. These tests are more Valuable if made in conjunction with control tests made with distilled water or i^vatcr known to be pure.

— Purifjing Water by Electric Light. —

MM. Jules Oourmont and Nogier have gust made a very interesting discovery — pamely, a simple physical method of sterilising ijyater. AU that ie necessary is to immerse in the water to be sterilised a quartz inereury vapour lamp" traversed- by en. electric- current. This gives off a green light, and in one minute water containing numerous bacteria i 6 completely sterilised over an area- of from 30 to 50 centimetres around the lamp, an effect presumably due tg the ultra- v.iolefc rays * emitted by the electric tube. The water is in no way altered, neither is jt T/armed. Lamps imflnersed permanently in the delivery pipes of a water supply -will, a Xianeet correepondent concludes, "assure its purity, provided only that the water be clear, as is •the case when it is derived from springs.

— Perils of ".Wireless."-

According to M. P. Bellile, a French .aaval surgeon on board the Descartes, which has been engaged in the campaign in Morocco, says the Lancet, the- members of the ship' 6 company who were employed in ■wireless telegraph duty developad various affections in consequence of the action of "the Herztian waves. Most commonly the telegraphists complained of their eyes, a slight cosnjisactivitis similar to that occurring among those who"work>with arc lamps being found. In order to protect the eye^ from damage by the ultra-violet raj-s of the electric emanation, which 'have a very powerful action, it wa© recommended that yellow or orange glasses should be worn. Not only were the eyes of the operators affected, but two cases of eczema — one of 4Jbe wrist and one of the eyelid, both very 'difficult to cure — were discovered. Lastly, one of the officials who had been employed for several years in wireless telegraphy x Buffered from painful palpitation of the heart, which came on after for any length of time *t the instruments for Sending messages. This man was quite free from any organio lesion of the heart. ' — Wireless Trains and Battleships. —

Dr Millener has devised a three-ton electric truck, which he drives exceeding slowly or at full spaed ahead -by a finger on the (keys of .a wireless device. The guiding waves of ether eontrollecT by this modern (wizard leap through soace and move til© [ponderous car, which "nauls a load of 20 tons. A mysterious "selective device." which is the inventor's secret, gives the " remote control " of the vehicle. Remote control now makes it possible for railroad •signals to be operated at any distanoe. and trains can be guided and Steamships steered at a distance, and the Wireless airship can be worked with no one aboard .

— Flora of Tiji. —

At the March meeting of the Linnean Society of London ilies L. S. Gibbs read a paper entitled "A Contribution to the Montane Flora of Fiji, including Cryptograms, with Ecological Notes." The Fiji group consist© of 200 islands, only 80 of »vhich are inhabited; Viti Levu is about $100 square miles in area, with forest-ciad mountain ranges, the highest point being Mount Victoria, 4000 ft in height. The (botanical history of the group begins with £he visit of H.M.S. Sqlphur, in 1840, and in the eazne year the Wilkes expedition touched at the island*. The Herald called in 1856, and Da* Seeman visited the group in 1850-1861. and embodied hi* results in hhei c "Flora Vitiensis." Mr Home, director of the Botanic Gardens at Mauritius, spent a year collecting-, in the late seren ties. Thanks- j to these investigators, the flora of the lower parts of the chief islands axe fairly well known. The author, therefore, decided to oonfine her investigations to the region lying 2900 ft or mope above the sea and the three spring months of August, September, and October -were spent at i^adarivatu, the highest inhabited point. From the collections, the flora may be described as Indo-Malayan. They contain about 40 new species and many new reooids. Thus, of the eight species of Piper, Mr C. deCandolle found .five to be new; j end of Peperomia, all seven proved novel- 1

'• ties'. The introduction concludes with come ' observations as to the origin of the flora, and is followed by a systematic enumeration of the whole collection. i — Reported Case of Cancer Cure by

Radium. —

I News of what is described as " a remarkj able cure of oa-ncer by radium " comes j from the Fiower Hospital, New York, | where Professor Dieffenbach and Dr Hel- ■ muth haxe obtained results in a easa which ! have caused them to express the belief that a final victory in the war with cancer is in sight. Six months a.30 an elderly man was admitted to the hospital suffering from a cancerous growth, as large as a child's head, in the stomach. The tissue was examined under the microscope, and showed beyond the possibility of a doubt ihat it wa6 peculiarly malignant It could not be operated upon, because the roots • were too widespread. Professor Dieffenbach became interested in the case, and ■called in Dr Helmuth, and after a consultation they obtained the patient's consent to us© radium.

Three incisions were made into the growth, and a small gpclatine capsule containing a tiny speck of radium, the total cost of which was £20, was inserted in each incision, after which the cuts were sewn up. The gelatine dissolved, and the radium began its direct action~on the cancer. The first effect was the c;reat prostration of the patient, who was in a highly nervous state and generally run down when admitted to the hospital But he soon began to mend, and five weeks after the operation the growth was greatly reduced in eize, and the patient was allowed to go home. Another examination, which was made some weeks later, showed that the cancer had entirely disappeared, the only trace remaining being a small lump, smaller than a pigeon's egg, which does not display any symptoms of cancer, and is simply a nodule of the scar tissue, such as remaiirs after healing any moderateW sized wound. The patient gives every evidence of a complete cure. — Apples Are Electrio Batteries. —

An interesting discovery has been made by an English electrician. It points to the fact that fruit, including nuts as well as grapes, apples, or oranges, and vegetables are small secondary electric batteries or storage cells. True, ihe power is slight, varying with the nature of the fruit or vrgotable, but, nevertheless, a certain amount of electricity is stored within, the presence of which can be detected if a sufficiently delicate galvano-meter is used. The earth is ahvajs charged with negative and the ail with positive electricity : the charging of the earth being secured by water, which acts as the electrolyte. In plant and vegetable life the electrolyte represented by the sap is in constant circulation so long as the soil conducts, and the cells ol the plant become converted 1 into small low-powered accumulators. there being- at least one cell so charged by the earth and air in all representatives of the plant kingdom, whether tree, fruit, or vegetable. In the course of his experiments with several types of fruit the investigator found the apple to be the most, powerful eell — i.e., having the greatest degree of electric potential, w.hile the orange was also found to be of large capacity. In thi6 latter instance, and the peculiarity applies to all such fruits where the flesh is divided into separate sections, each alternate division is positively charged, the cjlls being insulated from one another by the skins enclosing each section. Such fruits, therefore, constitute in reality a combination of storage cells, additionally insulated by the rind or peel. In the case of the apple or pear the positive cell was found to comprise the fleshy portion, the corp constitutine the negative cell. By cutting such a fruit in half, the construction of the system may be plainly followed. The experimenter is continuing his experiments in th-e ?a ne direction, and many interesting d-sif'opments respecting Nature's electric i^pfsm. and the possible value of such from a dietetic point of view, are anticipated.