184 REPORTS OF INVESTIGATIONS AND PROJECTS. 



peaches, nectarines, apricots, quinces, plumcots, cherries, raspberries, and 

 numerous other fruits. New forage plants, new roses, bulbous plants, orna- 

 mental, nut, and forest trees, and field crops have been grown, and several 

 collectors are employed in securing seeds of wild plants from remote sections 

 of the earth. 



CHEMISTRY. 



Acree, S. F., Johns Hopkins University, Baltimore, Maryland. Grant No. 

 498. A study of tautomerism and catalysis by the use of physico- 

 organic methods. (For previous reports see Year Books Nos. 4 and 6.). 



$500. 



Professor Acree submits the following abstracts of several articles on in- 

 vestigations carried out with the aid of grants from the Institution : 



Ueber die Reactionen tautomerer Saeuren iind Sake mit Diazomethan und 

 Alkylhaloiden. (Berichte der deutschen chemischen Gesellschaft, 41, 3199— 

 3236.) — This article is a short abstract of the quantitative work on tautom- 

 erism accomplished during the past three years under the direction of 

 Professor Acree. A full account of the work will appear later as a mono- 

 graph when several phases of the problem now under way are completed. 

 The theory which was presented tentatively (Year Book, No. 6, p. 178) to 

 account for the phenomena of tautomerism in the urazole series may be stated 

 as follows: The urazole, or its salt, reacts with an alkyl halide, or other 

 reagent, and forms two or more derivatives in constant ratio, because the 

 tautomeric urazole, or its salt, is really a mixture of two or more tautomeric 

 acids, or salts, in constant equilibrium, each tautomeric form of which reacts 

 with the alkyl halide or other reagent in independent side reactions. This 

 theory has been very useful to us in the prediction of all the quantitative 

 facts known at present, and in opening up new lines of research. With the 

 necessary modifications it has been applied to the reactions of many other 

 important classes of tautomeric compounds, such as the phenolphthalein 

 series, acetoacetic ester series, etc. 



The following quantitative relations have been predicted and verified ex- 

 perimentally: (i) The equilibrium is between the molecular forms of the 

 urazole salts and not between the anions. The alkyl halide reacts with the 

 anion and yields a complex anion which decomposes into the ester and a 

 halide ion. (2) Different salts have different equilibrium constants and 

 yield with a given alkyl halide different ratios of isomeric esters. Different 

 salts, since they are dissociated to different degrees, react with different 

 velocities with the same alkyl halide. C3) The equilibrium constant of the 

 salt and the ratio of the stable isomeric esters do not change appreciably 

 with a change in temperature. (4) A change in the solvent produces a 



