Calendar: 1876-1877 Page 556

556 CLOTHWOBKEBS' SCIENCE EXHIBITION 15 Describe tbe spectroscope and shew how it may be em- ployed both to detect the presence of substances on the earth and in the sun Describe clearly what the spectrum of the sun is like IV-Cijtmiitvn What elements are contained in silica Mention some natural and artificial products of which it is principal in- grediept Air is mixture and water is compound point out the distinction and give the chief reasons for it What do you understand by the term "atomic weight" How is the atomic weight of compound body calculated Give an example State the composition of common salt and describe pro- cess for extracting one of its elements in state of purity Name the elements usually contained in organic substances and give their atomic weights Describe the most important physical and chemical cha- racters of catbonic acid gas Bad silver coin contains tin and lead in what respect would the action of nitric acid upon it differ from that upon genuine coin What is iron pyrites Write its formula and give methid of distinguishing it from gold One cubic inch of carbonic oxide is mixed with two cubic inches of oxygen and exploded in the endtometer What is the volume of the gas after explosion and how much of it is ah- eorbed on shaking with potash -Sotanp Give the general characters and structure of starch Describe the structure of stomata-hairs-glands and receptacles of secretion