iili]iiH-;itU!s. a cut of 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 siu-rounded by a water jaclcet which in turn 

 is connected with a flasl^ containing water. Tlie flask and jacket are so 

 arranged tliat water of any dt'sired temiierature can be siphoned from 

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

 temperature between 0° and 100° C. A thermometer inserted in the jacket 

 indicates the teniperatui-e of the water. At the lieginning of the experi- 

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

 the tiask should hold several times the volume of the jacket. By the 

 nietliod of siphoning the change in tcnipeature is so gradual that the 

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

 passes through, and there is no danger of l)reaking the burette. With the 

 apparatus each law may I)e 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 l)e shown 

 that all obey (practicallyl the same laws. 



Some ^s-Ketg-Tv-Hexene Derivatives. 



James B. Garner. 



A study of the reactions which might be brought about between ben- 

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

 cold (15° O. ) alcoliolic sodium ethylate, was begun several years ago^ At 

 that time it was found that benzoin is added to benzalacetone giving rise 

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

 into 3— I-5-triphenyl-l-oxy-^2-keto-R-liexene. This substance had 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 greater, the reaction takes place more smoothly 

 and th3 product formed is purer than wlien potassium cyanide is used. 

 Knoevenagel has made an exhaustive study of the ^s-keto-R-hexene de- 



* Dissertation, Chicago, 1897, p. 17. 



^ Berichte, S6, 65. 



^ Amer. Chem. Join-. XXII, 250. 



12— Aciidemy of Science. 



