TKANSACTIONS OF SECTION B. 641 



bodies have to be sought in large amounts of a compound or mixture, such as are 

 all samples of commercial iron and steel. Li this class of analyses the percentages 

 of carbon and phosphorus may be as low as 0'15 per cent, and O'Ol per cent, 

 respectively, and yet these small amounts will have quite marked effects in the 

 steel which contains them. 



In order to bring about a greater uniformity of analysis in the countries 

 which are the principal producers and users of iron and steel, it is proposed to 

 prepare a quantity of samples which shall be absolutely identical and to distribute 

 them to properly qualified analysts in those countries, who will then analyse 

 them and will interchange reports of their results with each other. 



By the above plan there will be in each country participating in the work a 

 quantity of metal identical with that in the other countries, and which has been 

 analysed with the utmost care by a considerable body of chemists, so that its 

 composition may be said to be known authoritatively and beyond dispute, and 

 which will thus constitute international standards. 



The standards so obtained will serve two important purposes. First, they will 

 show, in the course of their preparation, the relative agreement in processes and 

 results habitually arrived at by the chemists of different countries. Second, these 

 standards being distributed to certain custodians, it may be possible to furnish 

 small portions of them to chemists who may make application for the purpose of 

 checking their individual work and obtaining a measure of their accuracy. Also, 

 as new analytical methods are constantly being invented, it will be of great 

 advantage to have a standard metal on which to test them. 



The details of the best method of securing the above ends should be the work 

 of a committee. ^ 



Professor Hermann Wedding, of Berlin, and Professor Richard Akerman, of 

 Stockholm, and myself have already considered the general plan, and have given 

 provisional assent to it and to the following suggestions :■ — 



First. The analysis shall be made for total carbon and for phosphorus. This is-, 

 all which it is advisable to demand, but other elements may be added at the wish 

 of any analysts for the samples in their hands only. 



Second. The samples shall be of the following composition (or temper) in . 

 carbon, as nearly as is practicable. 



Carbon = 1-3% 0-8% 0-4% 0-15% 



and all the other elements shall be kept down to the customary proportions for 

 steel of medium quality. 



Third. The samples shall be in the form of drillings, uniformly and carefullj 

 mixed, and quantities not less than forty kilogrammes for each temper : this would 

 mean not less than 160 kilos, for the whole. 



Fourth. These samples shall be equally divided and sent under seal to properly 

 accredited persons in Sweden, Germany, England, and the United States. 



Fifth. The analyses shall be made in each country independently, and the- 

 report of the results obtained shall be sent to each of the proper representatives of 

 the other countries participating in this plan. 



Sixth. If there should be an important disagi'eement in these reports it 

 shall then be the duty of the parties to this agreement to appoint an international 

 committee to whom the whole subject shall be referred. If, however, the reports 

 differ only slightly then the average of all the reports sliall be deemed the true 

 composition of the international iron and steel standards. 



6. On the Action of Light on Water Colours. 

 By Arthur Richardson, Ph.B. 



In this paper the author discusses the effect of light on colours, and draws 

 attention to the very important part played by moisture in assisting their decom- 

 position. Unstable colours are divided into two groups : — 



1st. Those which bleach by oxidation under the combined influence of light 

 1888. T T 



