AUCKLAND INSTITUTE. LECTURE ON "ALLOYS."

Te Aroha News, Volume VII, Issue 384, 13 July 1889, Page 4

AUCKLAND INSTITUTE. LECTURE ON "ALLOYS."

Auckland, June 10. Lust ovening, in the Museum Buildings, under bho auspices of the Auckland Institute, Profossor F. D. Brown dolivered an intei-osf-ing, popular lecture on "Alloys." Professor Thomas presided, and there was a good attendance ot persons interested in mining and scientific pursuits, and a number of ladies. Professor Brown said that the subject of alloys was one that had not hitherto received such an amount of popular attention as it should have. The number and variety of alloys from different metals might be infinitely multiplied. He illustrated his remarks by demonstrating experimentally the process of producing zinc alloy, and the mode of colouring liquids by moans of introducing iodino into the vessel containing the fluid. He roforred to the process of solution in connection with liquids as well as solids. Speaking of the propeities of metals and mineral 3 , ho said that, apart from the technical interest the subject had for engineers and otncis profossionally, there weie various points in connection with alloys which wcic oi popular interest to all pet sons, such as the change in colour, taste, and ductility of metals when alloyed, and these changes would gWe ri3e to a great deal of thought, Retcienoe was made to Mr Parkos, who rccontSy visited Uio colony on business connected with his celebrated patented smelting furnace works for separating the natural alloy of silver and lead oro into two distinct components. One especially notable feature in metals capable ot being alloyed was what might be termed tho %c conductivity " or capability of conducting and transferring sensations ot elcctiicity and heat. His statements legaiding this weic amplified by diagrams illu&tratingthe action of conducted electi icity and theineandesccnt light. One other change of great popular and sciontiiic interest in alloys was tho lowering of the fusing-point ot various metals. The degrees of heat ab which different metals melted were very diverse, gold requiring about the highest degree of heat to bring to a state of lusion. One important law of alloys was that the addition of, say, one moleculo per hundred of a certain substance to anothor in which it would dissolvo had the effect of lowering tho fusing point of the larger component of the alloy. This law of the lowering of the fusion point of mixtures was a mo&t important one in the study of chemistry, and had first attracted attention and become known through the scientific observation of the familiar solder of the plumber. The alloy of copper and aluminum was referred to — a strong, tenacious, ductile substance, of much tho same colour as gold, and a most usetul subject for mining purposes. Some compound substances commonly desciibcd as alloys wero not in reality allows in the true scns>o of the word, such as case iion, which was not an alloy, but an admixture ofcaibon with iron ore. The piofessor concluded his lecture with other experiments showing tho nature of alloys, and a(. the close was accorded merited applause for hib discourse on a scientific subject of popular interest.