BRAIN ACTIVITY.

Auckland Star, Volume LXVI, Issue 269, 13 November 1935, Page 17

BRAIN ACTIVITY.

SENSITIVE IN SLEEP.

WATER-BORNE DISEASES. REMEDY FOB. " BLEEDERS." (By a Special Correspondent.) WASHINGTON, ' The brain asleep is electrically active and extremely sensitive. The" discovery of electrical waves, initiated in the cortex by slight sounds which do not awaken the sleeper, is reported in "Science," the organ of the American Association for the Advancement of Science, by Alfred L. Loomis, E. Newton, Harvey and Garret I-lobart. These waves, detected by recording devices attached to the skull, have frequencies of from 20 to 30 per second and amplitudes of from 10 to 50 microvolts. They are undoubtedly of cortical origin and differ for individuals. They appear in trains, at intervals of 30 seconds to t\yo minutes, and each lasts from five to twelve seconds. The amplitude builds up regularly to a maximum and then falls. There is no correlation with heart beat or rate of respiration. Such a train can be started by rustling paper, coughing, closing a door gently, or starting low conversation. The sounds are not loud enough otherwise to disturb the sleeper. The ame sounds do not start up these electrical waves when the individual is awake. Neither docs the man's own snoring initiate them, except that they may be started by a single snore. The experimenters also found recurring outbursts of waves not associated with any disturbance and for which they can deduce no cause.

A Romance of Science. Devious are the paths of science. Dr. A. F. Woods, former scientific director of the Department of Agriculture, tells of one of the most remarkable progressions from the apparently trivial to developments of great medical and commercial importance, and the story comes partly from the files of the Department itself. Familiar to everyone is the green slime, known as "frog spittle," which gathers on ponds and stagnant streams. It consists of string-like colonies of algae, primitive, one-celled plants. Nearly a century ago a Swiss biologist, Willielm von Nageli, attempted to study these as a matter of interest to pure science. He found that they would not grow in tap water, but he could not detect any chemical difference between this and the pond water in which they thrived. Von Nageli's curiosity was aroused and after numerous experiments he came to the conclusion that the algae poison in the tap water must consist of copper from the faucet. There was only one part of copper to 50,000,000 parts of

water, but this was enough to kill tlie primitive plants. He published his conclusions in an obscure "pamphlet'•which nobody read and which was forgotten for half a century. Actually he had discovered the most sensitive test of copper known to science. Fifty years later the Department of Agriculture received a letter from a commercial grower of water cress. "The "frog spittle" was choking his crop and he wanted to know what to do about, it. An American industry; whose prof? duct was valued at millions of dollars a year was seriously threatened. One of the experts, browsing around in the library, came on this forgotten pamphlet containing an account of Von Nageli"s' work. Deadly Bacteria Destroyed. The problem was solved .and the water cress industry saved. But this was only a beginning. WAter-borne clisGflSGSj: bjircly liGtird. of iri ."tliG Swiss biologist's day, had come to the fore. If minute traces of copper killed the algae, might these not also kill other one-celled organisms, such as the bacteria responsible for typhoid or cholera? They tried it out and it worked. It also killed certain fish. The experiments with copper had shown that mosquito larvae were killed by slightly higher concentrations —one part in about ten million. This discovery may have made possible the building of the Panama Canal. At least it greatly facilitated the work. The great canal might be considered as a permanent monument to the obscure Swiss biologist. „ x Still the end was not in sight. The specific lethal effects of traces of copper led to studies of its precise physiological effects on different kinds of organisms, and this led to the . discovery that it is essential for red blood cell formation in warm-blooded animals, and brought about the experimentation leading to the successful treatment of various forms of anaemia.

Venom Saves "Bleeders.* | The venom of one of the world's deadliest reptiles, Russell's viper of India, may have supplied a medicine which will save the lives of victims of the dreaded "bleeding disease" found conspicuously among the royal families ,of Europe. The blood of victims of this malady will not coagulate. As a result they may bleed to death from a slight wound. An accidental cut or the extraction of a tooth may prove fatal. This is due to an absence in the blood of a chemical substance known as prothrombin, the presence of. which is essential for the formation of the thrombin which is the actual coagulating agent. The blood of a person bitten by Russell's viper coagulates throughout the body very rapidly, causing death in a few minutes. Experiments are now in progress at St. Bartholomew's Hospital in London, reported in the British medical journal "Lancet," in which this venom in'dilutions of one part in 10,000 has been used successfully to coagulate the blood of the "bleeders." Cotton soaked with this solution is packed into the cavity from which a tooth has been extracted, with a rapid cessation of the blood flow. —N.A.N.A.)