586 TRANSACTIONS OF SECTION B. 



The following Papers and Reports were then read 



1. Description and Exhibition of Diagrams used by Dalton in illustrating 

 his Atomic Theory. By Dr. H. P. Coward and Professor A. 

 Harden. 



2. Preliminary Observations on the Nitrite of Vinylacetic Acid. 

 By Professor Paul Henry, University of Louvain. 



Several methods have been tried to prepare the substance CH.2=CII — CHg — CN. 

 One might mention the action of moist KCN on allyl iodide, which gives, by a mole- 

 cular transformation, the nitrile of crotonic acid CH3 — CH=CH — CN, and also the 

 action of solid KOH on the nitrile of chlorbutyric acid CH2CI— CH2— CH2— CN, 

 which, however, yields a trimethylene derivative 



^2^\CH— CN. 



It is believed that the nitrile of vinj'lacetic acid has been prepared by heating 

 for several hours at a temperature of about 120'' C. a mixture of C3H5I and anhydrous 

 Cu.2(CN)2, when a product is obtained which boils at 118° C. and has no smell of an 

 isonitrile derivative. 



In order to identify the substance thus obtained, the oxidising actioE of a cold 

 neutral solution of KMn04 was first tried. Malonic acid, which should be the 

 characteristic oxidation product of this nitrile, was not definitely obtained, probably 

 because oxidation had proceeded too far. 



The action of organo-magnesium compounds to give acetones (CH2=CII — CH2 — 

 CO — R) was also unsuccessful, for the substances BrMgC2H5 and BrMgCjHj only 

 yielded resinous bodies. The action of ozone was next examined. The ozouide of 

 crotonic nitrile when treated with water gave acetaldehyde, but the syrupy ozonide 

 obtained from vinylacetic nitrile was found on analysis to possess the composition 

 anticipated, and when treated with water yielded no acetaldehyde. Its decom- 

 position products have been examined. 



3. Experimental Demonstration of a new Cadmium-V apom Arc-Lamp. 



By Dr. H. J. S. Sand. 



The cadmium-vapour arc-lamp exhibited, the use of which is recommended 

 for polarimetric and other purposes, is comparable in general principle with the 

 well-known mercury-vapour lamp. The lamp is constructed of quartz-glass, and 

 the cadmium is freed from oxide and dissolved gas by a process of filtration 

 while at the pump. It is hindered from adhering to the glass by the presence 

 of a small amount of a loose powder (zirconia) in the lamp. The metal is 

 melted by external heating before starting, and maintains itself in the molten 

 condition by the heat of the current. Once started the lamp may be kept 

 burning for an indefinite time. 



4. Joint Meeting with Section A. — Discussion on Eadio-active Elements 



and the Periodic Laiv. 



5. Report on Hydroaromatic Substances. — See Eeports, p. 79. 



6. Report on Transformation of Aromatic Nitroamines. 

 See Eeports, p. 82. 



7. Report on Dynamic Isomerism. — See Eeports, p. 81. 



