177 



niiiiaratus. a cut ol' which is presented, was devised to overcome the diffi- 

 culty. It consists of an ordinary graduated gas burette connected with a 

 reservoir for mercury and surrounded l)y a water jacket which In turn 

 Is connected witli a fiask contahiing water. The flask and jacket are so 

 ari'anged that water of any desired temiHrature can Ite siphoned from 

 the former through the latter, thus heating the gas in the burette to any 

 temperature lietween (i° and ]00° C. A thermometer inserted In the jacket 

 indicates the tempei'atiu'e of the water. At the beginning of the experi- 

 ment the water in the jacktt should be at the room temperature, and 

 the flask should hold several times tlie volume of the jacket. By the 

 metliod of siphoning the change in tcmpeature is so gradual that the 

 gas is heated to thf water temperature almost as rapidly as the latter 

 passes through, and there is no danger of breaking the burette. With the 

 apparatus each law may be deduced separately with a fair degree of 

 accuracy. Then the two laws united and the results compared with those 

 found mathematically from a combination of the two. The idea of ab- 

 solute zero is illustrated in a very clear and convincing way. If desirable 

 the burette may be filled with different gases, and thus it may be shown 

 that all obey (practically) the same laws. 



Some Ao-Keto-Iv-Hexene Derivatives. 



James B. Garner. 



A study of the reactions wiiicii might be brouglit about between ben- 

 zoin and unsaturated aldehydes, ketones, and esters through the agency of 

 cold (15° C ) alcoholic sodium ethylate, was begun several years ago^ At 

 that time it was found that beuz(')in is added to benzalacetone giving rise 

 to a 1.5 diketone whicli by loss of water and ring formation, is converted 

 into 8-4-5-tripheuyl-4-oxy-_2-keto-R-hexeue. This substance Iiad previ- 

 ously been prepared by Professor Alexander Smith^, using potassium cyan- 

 ide as condensing agent''. When sodium ethylate is used as condensing 

 agent, the yield is much givater, the reaction takes place more smoothly 

 and the product formed is purer than when potassium cyanide is used. 

 Kuoevenagel has made an exliaustive study of the ^s-keto-R-liexene de- 



^ Dis.sertation, Chic-ngo, 1897, p. 17. 



= Berichte, 26, 65. 



^ Amcr. Chem. Jour. XXFI, 250. 



12— Aciidemy of Science. 



