372 transactions of the american institute. 



Aniline, Green, 



This compound was first made by M. Eiis(>l)o. It is now readily pvo- 

 diux'd by dissolving ir)0 grainos of crystallizod snlpliato of rosaniliiie in 450 

 granics of cold, diluted sulplinric aeid (three parts acid to one of water). 

 When the solution is complete, 225 grames of aldehyde are added. The 

 mixture, after being stirred, is heated in a water bath. From time to time 

 a drop of the mixture is taken up with a stirring-rod and dropped into 

 slightly acidulated water, and as soon as a deep green solution is obtained 

 the reaction is stopped. The solution is then pourecf into 30 litres of boil- 

 ing- water, and 450 grames of hyposulphite of soda dissolved in the smallest 

 possible quantity of water, is gradually added, The whole is now boiled 

 for some minutes. All the grcjen remains in the aolution, which may be 

 applied to dye silk. The green is very beautiful, especially in artificial 

 light, which distinguishes it from all other shades of the same color. 



Variation and Transmutaton of Species. 



Mr. A. R. Wallace read before the Anthropological Society a paper con- 

 taining the following statements : 



1. Peculiarities of every kind are more or less liereditary. 



2. The offspring of every animal vary more or less in all parts of their 

 organization. 



3. The universe in which these animals live is not absolutely invariable. 



4. The animals in any country (those at least which are not dying out) 

 must at each successive period be brought into harmony with the surround- 

 ing conditions. 



These are all the elements required for change of form and structure in 

 animals, keeping in exact pace with changes of whatever nature in the sur- 

 rouiiding universe. Such changes must be slow, for the changes in the 

 universe must be very slow; but just as these slow changes become import- 

 ant, when we look at the results after long periods of action, as we do 

 when we perceive the alteration of the earth's surface during' geological 

 epochs; so the parallel changes in the animal form become more and more 

 striking, according as the time they have been going on is great, as we see 

 when we compare our living animals with those which we disentomb 

 from each successively older geological formation, 



Relation of Periodic Times. 



Mr. Finlaysou, of Dover, has found that the period of the rotation of the 

 earth on its axis is in the same proportion to the time of the revolution of 

 the moon around it, as the rotation of the sun on its axis is to the year of 

 the planet Mars. 



Testing Chain Cables. 



Mr. F. A. Paget, C. E., London, states that the average tenacity of those 

 bars of which the links were made was twenty-four tons per square inch; 

 of this, 28.15 per cent is lost in the finished link, (Twing to the form of the 

 link, the stress on the inside of the crowns, the bending and the welds. 

 The government hydraulic test is 11.46 tons per square inch, and the per- 

 manent set resulting thereof is from 1-22 to 1-15 its length This he be- 



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