NA TURE 



\_A T ov. 6, i! 



value must almost invariably be quantitative. It is little less 

 than a disgrace to the medical profession that a subject of such 

 vital impartance as chemistry should be so neglected. 



If, however, we are to make any change in our method of 

 teaching science, if we are to teach science usefully throughout 

 the country, two things are necessary : teachers of science must 

 take counsel together, and the examining boards must seriously 

 consider their position. There can be little doubt that in too 

 manv cases the examinations are suited to professional instead of 

 to educational requirements ; and that the professional examina- 

 tions are often of too general a character, and do not sufficiently 

 take into account special requirements. 



APPENDIX 



Problem : to Determine the Composition of Air 

 N.B. — Immediately after performing each experiment indi- 

 cated in this and subsequent papers, write down a careful de- 

 scription of the manner in which the experiment has been done, 

 of your observations and the result or results obtained, and of the 

 bearing of your observations and the result or results obtained on 

 the problem which you are engaged in solving. Be especially on 

 your guard against drawing conclusions which are not justified 

 by the result of the experiment ; but, on the other hand, en- 

 deavour to extract as much information as possible from the 

 experiment. 



1. Burn a piece of dry phosphorus m a confined volume of 

 air, i.e. in a stout Florence flask closed by a caoutchouc stopper. 

 Afterwards withdraw the stopper under water, again insert it 

 when water ceases to enter and measure the amount of water 

 sucked in. Afterwards determine the capacity of the flask by 

 filling it with water and measuring this water. 



N. B. — The first part of the experiment requires care and must 

 be done under direction. 



2. Allow a stick of phosphorus lashed to a piece of stout wire 

 to remain for some hours in contact with a known volume of air 

 confined over water in a graduated cylinder. After_noting the 

 volume of the residual gas, introduce a burning taper or wooden 

 splinter into it. 



N.B. — The residual gas is called nitrogen. 



3. Burn a piece of dry phosphorus in a current of air in a tube 

 loosely packed with asbestos. Weigh the tube, &c, before and 

 after the experiment. 



4. Repeat Experiment 2 with iron borings moistened with 

 ammonium chloride solution. Preserve the residual gas. 



5. Suspend a magnet from one arm of a balance ; having 

 dipped it into finely divided iron, place weights in the opposite 

 pan, and when the balance is in equilibrium, set fire to the iron. 



6. Pass a current of dry air through a moderately heated tube 

 containing copper. Weigh the tube before and after the experi- 

 ment ; also note the alteration in the appearance of the copper. 



7. Strongly heat in a dry test tube the red substance obtained 

 by heating mercury in contact with air. At intervals plunge a 

 glowing splinter of wood into the tube. Afterwards note the 

 appearance of the sides of the tube. (Before performing this 

 experiment ask for directions.) 



N.B. — The gas obtained in this experiment is named ,n 1, .'. 



8. Heat a mixture of manganese dioxide and potassium chlorate 

 in a dry test tube, and at intervals plunge a glowing splinter into 

 the tube. This experiment is to acquaint you with an easy 

 method of preparing oxygen in quantity. 



9. Prepare oxygen as in Experiment S, and add it to the 

 nitrogen from Experiment 4 in sufficient quantity to make up the 

 bulk to that of the air taken for the latter experiment. Test the 

 mixture with a burning taper or splinter. 



10. Dissolve copper in nitric acid and collect the escaping gas 

 (nitric oxide) ; add some of it to oxygen and some of it to air. 



11. Fill a large flask provided with a well-fitting caoutchouc 

 stopper and delivery tube with ordinary tap water and gradually 

 heat the water to the boiling-point ; collect the gas which is 

 given off in a small cylinder and add nitric oxide to it. Also 

 collect a sufficient quantity in a narrow graduated cylinder and 

 treat it as in Experiment 2. 



Comparative Study of Silver and Lead 

 Silver. — Symbol, Ac (Argenlttm). Atomic weight, 107 '67. 



Specific heat, '05701. 



Lead. — Symbol, Pn. {Plumbum). Atomic weight, 2o6"47. 



Specific heat, '03140. 



I. Determine the relative density of lead and silver at a known 



temperature by weighing in air and in water.! 



2. Separately heat known weights of lead and rilver for som e 

 time in the air, allow to cool, and weigh. 



3. Separately convert known weights of lead and silver into 

 nitrates, and weigh the latter. From the data thus obtained 

 calculate the equivalents of lead and silver. 



4. Convert the known weights of nitrates thus obtained into 

 chlorides, and weigh the latter. 



5. Compare the action on lead and silver of chlorhydric acid ; 

 of dilute and concentrated sulphuric acid, using the acid both 

 cold and hot ; and of cold and hot nitric acid. 



6. Using solutions of the nitrates, compare their behaviour 

 with chlorhydric and sulphuric acids, hydrogen sulphide, potas- 

 sium iodide, and potassium chromate. Ascertain the behaviour 

 of the precipitate formed by chlorhydric acid when boiled with 

 water, and when treated with ammonia solution. 



7. Compare the behaviour of lead and silver compounds on 

 charcoal before the blowpipe. 



8. Tabulate the results of your experiments with lead and 

 silver in parallel columns. 



9. Ascertain whether the substances given you contain lead or 

 silver. 



10. Determine silver in an alloy of lead and silver by cupel- 

 lation. 



1 1. Study the method of determining silver volumetrically by 

 means of a standard solution of ammonium thiocyanate. Deter- 

 mine the percentage of silver in English silver coinage. 



12. Determine silver as chloride by precipitation. 



[3. 1 'issolve a known weight of lead in nitric acid, precipitate 

 it as sulphate, collect and weigh the latter. 



14. What are the chief ores of lead and silver? How are lead 

 and silver extracted from their ores ? How is silver separated 

 from lead? How is it separated from burnt Spanish pyrites? 

 What are the chief properties and uses of lead and of silver ? 

 State the composition of the chief alloys of lead and silver. 



TRANSACTIONS OF THE NEW ZEALAND 



INSTITUTE 

 \70LUME XVI. of the Transactions and Proceedings 0/ the New 

 Zealand Institute contains the more important memoirs laid 

 before its eight incorporated Societies during the year 1S83 and the 

 first weeks of 1884. It forms a bulky volume of about 650 

 pages, and is illustrated by 44 plates. It speaks a great deal for 

 the energy of the able editor, Dr. James Hector, F.R.S., that 

 he has in so short a time reduced such a mass of material into 

 order, and that the volume should be issued in May of this year. 

 While we think the illustrations still leave something to be desired 

 as to their general style and execution, this volume is extremely 

 creditable to the colony, and the amount of accurate research re- 

 corded will, if continued, soon make New Zealand one of the most 

 completely investigated regions of the world. Of the 57 articles 

 selected from the papers read before the local Societies, 25 relate 

 to zoology, 22 to botany, 5 to geology, 1 to chemistry, and 4 to 

 miscellaneous subjects. While of the titles of these papers we 

 append a classified list, some few of them merit a more par- 

 ticular reference. 



Mr. E. Meyrick contributes a third series of his descriptions of 

 New Zealand Microlepidoptera, treating this time of the (Ecopho- 

 ridse. This is the principal family of the Tineina in New Zealand, 

 as is also the case in Australia. Some 67 species are recorded, of 

 which 55 are particularly described, but the total number of 

 species it is thought will be much more considerable. In New 

 Zealand the family constitutes about a sixth of the entire Micro- 

 lepidoptera, in Australia it forms more than a fourth, whilst in 

 Europe it is about a thirtieth. It seems strange that, while this 

 family occupies so prominent a position in both New Zealand and 

 Australia, no species as far as is yet known is common to both. 

 Fourteen genera are found in New Zealand ; of these ten are 

 endemic, three occur also in Australia, and one is cosmopolitan. 

 Of the three genera shared with Australia, two (Eulechria and 

 Phlreopola) are large and typically Australian genera, represented 

 in New Zealand by three species, obviously mere stragglers ; the 

 third (Trachypepla) is a typical New Zealand genus, probably 

 of considerable extent, and is represented in Australia by two 

 species only, evidently also stray wanderers. Of the ten en- 

 demic genera, none are very closely related to Australian forms. 

 It would therefore appear that, while it is not improbable that a 

 slight interchange of species has taken place at some not exceed- 

 ingly remote period, it seems nearly certain that the group is of 



