SCIENCE NOTES.

Hokitika Guardian, 6 November 1924, Page 4

SCIENCE NOTES.

WONDERS OF THE MiSCKOSCOPE

.Aliseroscopie analysis of cross-sec-tions ol fragments of a fossil fern have revealed the living anatomy of giant plants which nourished aeons ago, Professor W. T. Gordon, of King’s College, London, announced to the Hritish Association for the Advancement of Science at Toronto. Petrified stems the size of trees, twigs clothed with hark, and buds with their leaves attached recently found in Haddingtonshire, England, show that this fern was much simpler than formerly supposed hy botanists.

CHINA NOT OYER-POPULATED. The popularly accepted idea that China is overcrowded, and that the country cannot support a greater population was refuted hy Professor p. M. Roxby, of the department of geography of the University of Liverpool, in an address before the Hritish Association for tin* advancement of Science at Toronto. The cilies of China, which are all that most travellers see of that country, are unquestionably ovecrowded. Professor lioxby admits, and for some time there is scant prospect of a readjustment in population. Rut there arc still great areas thinly populated, and when the political status ol the country becomes mere settled and better means of communication developed, a redistribution of the population will take place. MAKE CHOPS FIT SOIL.

A suggestion that is expected to have much significance in the scientific development of diversified farming is put forth by Dr F. T. AN berry, of the Rureau of Chemistry, S. Department of Agriculture. It is tliaL the farmer, instead ol trying lo force Ills soil to produce the kind of crop he thinks lie must raise hy the heavy jiud expensive application of certain kinds of fertiliser, should study his soil and find what kind of crop it will grow most economically under natural conditions. Forcing a soil to change its chemical nature by liming or other fertiliser operations to make it lit a conventional crop is poor business when some other kind ol crop may he grown on it. at a profit as it stands. There are begriming lo he available considerable masses of scientific data, indicating the preferences of various kinds oT plants as to the chemical conditions in tile soils in which they grow best, and there already exist several practical and rapid methods of getting soil reactions. The logical practice. Dr AYherry thinks, in to find the range of conditions your field (lifers, and then to find what kind of plants most ncarlv lit those conditions. THE HEART OF A DIAMOND.

AYhat’s the difference between an en gagement ring and a lead pencil!' 1 H other words, what’s the difference be tween diamond and graphite’:' Roth an pure carbon. Professor AN . L. Bragg recently awarded the Nobel Prize ii physics, explained the points of diver genre in a lecture at the convcnlioi of the Hritish Association for the Ad vnncemeiit of Science at loronlo re contlv.

‘•Tn the diamond.” lie said, “each atom of carlion is surrounded by four similar atoms grouped symmetrically around it, and all at the same distance away, namely. onc-and-a-half hundred-millionths of a centimeter, a distance which the X-ray enables us to measure, to one part in a thousand. NN e arc struck by the remarkable grouping of the atoms into lings of six. Til

graphite three of the neighbours of the carlion atom draw even a lit He closer to it than the diamond, hut the fourth moves away. I lie crystal, is. in lac I. in layers. Each alum in a layer has three neighbours arranged symmetrically around it. Hut- it is a long way from one layer to the next. Ihe layers have so little hold on each other that they slide over one another very easily, lint, each layer is very tough in itself. It is the combination of these properties that, makes graphite so perfect a lubricator, although diamond, the other carbon crystal, will scratch anvt liing.” MAKING NITRATES.

A new process for the fixation of al inospherie nitrogen ill a form so il ea he used for fertilisers of explosives wa explained before the eheniieal seetio of the Hritish Association for the Ail vain cmeiil of Science hy Air NY. .1

Bolir. professor of «-!u*iili":il technology al lb'- 1 1 n i it'i'i :i I College of Science. I,.onion. NilroiO-n is n:i I iir.-itly a veto inert gas. ami it is (lillic'ilt to get iut' an active stale, so it- will coinl.iue with other elements, such as oxygen or hydrogen. 11l the commercial proecsso 1 an electrie spark or a metallic catalyst is used to gel the nitrogen to enter into combination. But Rrofessni Bone finds th.-t nitrogen can lie nefivati'il by proximity to carbon moeoxide ill combustion under pressure. Carbon monoxide can easily be procured in (plantit.v from blast furnaces nr by passing air through a bed of red hot coal. Will'll this gas is put togel.bewith air into a bomb under a pressure of tt hundred atmospheres and tho mixture exploded, the carbon monoxide unites with the oxygen of the air to form dioxide. Buf when this coniliinatinli takes place under such circumstances the heat prod need hv the combustion produces oxides of nitrogen from which nitric acid or nitrates of any sort can he readily derived. The nitrogen excited by the explosion of a mixture of carbon monoxide and air combines will) oxygen more readily than dues nitrogen, which lias been raised to a correspondingly high temperature by exploding a mixture of hydrogen and air.