461 Scientific Intelligence. 



added and the whole diluted with 20 cc water, the specific 

 rotatory power was — 3-0°. With l cc malic acid solution and 

 5 CC uranyl nitrate solution (diluted with water to 20 cc ) the 

 value of [a] D was —11°. With l cc malic acid solution, ip c KOH 

 solution and l cc uranyl nitrate solution, diluted to 20 cc , the value 

 of [a] D rose to —139°. And when to l cc of the solution of malic 

 acid, 2 CC KOH solution and 1-J CC uranyl nitrate solution were added, 

 and diluted to 20 ec ,[a] D reached — 475°. This maximum was attained 

 when to 1 molecule malic acid about 4 molecules of KOH and 

 from 1-4 molecules of uranyl nitrate was used ; the value then 

 being more than five hundred times greater than the value given 

 by the malic acid solution alone. Similar results were obtained with 

 tartaric acid and its mono-methyl ether ; with quinic acid and with 

 /-mandelic acid ; though in a less degree. The inactivity of i- 

 malic, z-manclelic and mesotartaric acid Avas not altered by the 

 uranyl salt. Acids such as c?-chlorsuccinic, ^-bromsuccinic and 

 f?-amylacetic, which contains no free hydroxyl group, show no 

 increase of rotatory power on adding the uranyl salt. The 

 author summarizes his results as follows: (1) Alkaline solutions 

 of uranyl salts produce both in aqueous and alcoholic solutions, a 

 marked increase of rotatory power in the case of optically active 

 acids; (2) this increase is conditioned upon the presence in the 

 acid of a free hydroxyl group; and (3) it reaches its maximum 

 when to one molecule of the oxacid (for example oxydicarbonic 

 acid) at least one molecule of uranyl salt is added, together with 

 the quantity of alkali required to neutralize the carboxyl groups 

 and also the acid contained in the uranyl salt (i. e. about 4 mole- 

 cules in all). — Ber. Berl. Chem. Ges., xxx, 2889-2895, December, 

 1897. G. F. B. 



3. On the Influence of the Silent Discharge on Atmospheric 

 Air. — A series of experiments has been made by Shenstone and 

 Evans on the influence exerted upon atmospheric air by the silent 

 electric discharge. Their conclusions are as follows : (1) Oxygen 

 diluted by nitrogen yields a higher proportion of ozone when 

 submitted to the influence of the silent discharge under given con- 

 ditions, than pure oxygen ; the proportion of oxygen ozonized 

 may be as high as 98 per cent. (2) If the process be not pressed 

 too far, no nitrogen peroxide will make its appearance. (3) The 

 presence of water vapor is very favorable to the production of a 

 high yield of ozone and retards the appearance of nitrogen per- 

 oxide. (4) At a certain stage in the process, depending on the 

 amount of vapor present and probably also on the temperature of 

 the gas, nitrogen peroxide is formed ; its appearance being almost 

 immediately followed by a rapid disappearance of the ozone, this 

 in its turn resulting in the destruction of most of the peroxide. 

 (5) That, as Andrews has stated, the presence of a trace of nitro- 

 gen peroxide renders it impossible to convert oxygen into ozone 

 by means of the silent electric discharge. And (6) nitrogen per- 

 oxide and ozone when moist do not mutually destroy each other 

 at 0°, or do so at a very slow rate, unless they are under the 



