754 



SCIENCE. 



[N. S. Vol. XXIII. No. 593. 



Tlie action of ozone on carbonyl derivatives 

 (aldehydes or ketones) is hardly less interest- 

 ing than its behavior towards unsaturated 

 compounds. Under similar experimental con- 

 ditions to those described above, ozone causes 

 the addition of one atom of oxygen to each 

 carbonyl group. 



> CO -f- O3 ^ > C: 0: O + 0,. 



These substances, which are peroxides, readily 

 react with water forming hydrogen peroxide 

 and regenerating the original carbonyl com- 

 pound. It will be observed that the peroxides 

 of aldehydes are isomeric with the acids which 

 may be derived from these aldehydes; thus, 

 heptoic aldehyde (oenanthol), 



CHsCH,CH,CH,CH,CH,CHO, 



yields the peroxide, CH3(CH,),CH: 0: 0, 

 which is isomeric with heptoic (oenanthic) 

 acid, 0H3(CH,),COOH. It is found that 

 such peroxides change spontaneously, after 

 some time, into the corresponding acids, a fact 

 which may have an important bearing on the 

 theory of the oxidation of aldehydes to acids. 



In the case of carbonyl compounds contain- 

 ing one or more ethylene linkages both the 

 above reactions occur simultaneously, i. e., 

 one molecule of ozone is added to each double 

 bond and one atom of oxygen to each carbonyl 

 group. 



Harries finds that ether appears to be 

 capable of absorbing unlimited quantities of 

 ozone; the product is very highly explosive. 

 These facts probably account for the mys- 

 terious ether explosions which occur in labora- 

 tories from time to time; ozone is produced 

 during many reactions, such as occur in 

 flames, is absorbed by ether and the explosion 

 follows when the ether is heated. 



RESEARCHES ON THE AMINO ACIDS, POLYPEPTIDES 

 AND PROTEIDS. 



Emil Fischer recently delivered a lecture, 

 under the above title, before the German 

 Chemical Society. The report of the lecture 

 occupies more than eighty pages of the 

 * Berichte ' ' and contains the chief results of 



^Ber. d. Chem. Ges., 39, 530 (1906). 



his labors in the field in question during the 

 past six years. It thus represents the cream 

 of several dozens of papers, and although it is 

 severely compressed, yet the author's name is 

 sufficient guarantee that the style is fasci- 

 nating and the material of the highest order 

 of merit. In this brief note it is, obviously, 

 impossible to do justice to the lecture, yet 

 some of Fischer's results and conclusions are 

 of such general importance that a brief out- 

 line of them should be given. 



The hydrolytic cleavage products formed by 

 the action of acids, bases, or enzymes on pro- 

 teids are chiefly mixtures of various amino, 

 hydroxyamino and diamino acids, belonging 

 to the aliphatic series, although similar de- 

 rivatives of the alicylic and aromatic series 

 are not infrequently found. Fischer's first 

 task was, therefore, to improve the methods 

 for the synthesis of the above classes of com- 

 pounds and to investigate their individual 

 properties, so as to work out methods for the 

 separation and identification of each sub- 

 stance when present in the mixtures already 

 mentioned. 



The second step consisted in the synthesis 

 of ' polypeptides,' which are amide anhydrides 

 of amino acids. Thus aminoacetic acid (gly- 

 cocoll, glycine), H,NCH,COOH, yields the 

 amide anhydride H,NCH,CONHCH,COOH, 

 which is termed glycylglycine and is a dipep- 

 tide. No limit can, as yet, be assigned to the 

 number of such compounds which may be pre- 

 pared; they usually crystallize well and are, 

 therefore, admirably adapted for purposes of 

 investigation. The most complicated one 

 which has been obtained up to the present 

 time is a heptapeptide. 



Synthetical polypeptides are, of course, 

 racemic, but those which are obtained from 

 proteids frequently exhibit optical activity. 

 Fischer has worked out several methods for 

 the resolution of his racemic compounds into 

 their optical antipodes. The results are in 

 complete accord with the current theory of 

 the asymmetric carbon atom. 



Fischer's efforts have not been confined to 

 synthesis; he has also investigated the com- 

 pounds formed by the resolution of some 



