402 



NATURE 



[May 27, 1920 



The report of the Council of the Illuminating En- 

 gineering Society, presented at the annual meeting on 

 May II, contains an interesting record of the past 

 session's work. Papers and discussions dealing with 

 photometry, camouflage, colour-matching, motor-car 

 head-lights, and lighting conditions in mines have been 

 arranged, the last in co-operation with the Council 

 of British Ophthalmologists and the Royal Society 

 of Medicine. The various committer's working under 

 the society, notably that conducting an inquiry into 

 eyestrain in kinemas, afford evidence of similar co- 

 operative effort. Special attention has been devoted 

 to industrial lighting in relation to health and safety, 

 and it is hoped that before long general statutory pro- 

 vision for adequate lighting will be introduced into 

 the Factory Acts. The society hopes now to be able 

 to resume its participation in the international treat- 

 ment of illumination, and is represented in the person 

 of its hon. secretary at the congress of the Royal 

 Institute of Public Health taking place this month 

 in Brussels. Following the presentation of the annual 

 report, a paper on portable kinema outfits was read 

 by Capt. J. W. Barber, several novel forms of ap- 

 paratus being shown. 



The work of Willstatter and his collaborators has 

 imparted considerable interest to that branch of bio- 

 chemistry which includes the formation of antho- 

 cyanins in plants. A suggestive paper on the subject 

 is contributed to the April issue of the Bioche^nical 

 Journal by O. Rosenheim. This author has isolated 

 in a crystalline form the red pigment of the young 

 leaves of the grape-vine, and has shown that it is 

 most probably identical with oenidin, the non-sugar 

 component of the pigment of the purple grape. This 

 is the first instance on record in which the red pig- 

 ment of leaves consists of free anthocyanidin. The 

 vine-leaves have been shown to contain also a colour- 

 less modification of the pigment, possibly in com- 

 bination with a carbohydrate or other complex. For 

 this compound the general name " leuco-anthocyanin " 

 is suggested; it is converted into anthocyanidin by 

 strong acids. The only representative of the family 

 Vitis characterised by the production of free antho- 

 cyanidin is the European species, Vitis vinifera, and 

 it is pointed out that this biochemical test may 

 prove useful in the investigation of genetic 

 problems. 



An interesting paper by Eiichi Yamasaki on " The 

 Chemical Kinetics of Catalase " has recently ap- 

 peared in the Science Reports of the T6hoku Imperial 

 University (vof. ix., No. i). The property formerly 

 attributed to all enzymes of accelerating the decom- 

 position of hydrogen peroxide is really a specific pro- 

 perty of catalase, which is contained as an impurity 

 in most enzyme preparations. The catalase used by 

 Yamasaki was obtained from the edible sprout of a 

 certain bamboo, Phyllostachys mitis, Riv. The 

 velocity of decomposition of hydrogen peroxide by 

 catalase is, in general, proportional to the concen- 

 tration of the enzyme and of hydrogen peroxide, but 

 the activity of the catalase decreases in the course of 

 NO. 2639, VOL. 105] 



the reaction. As to the cause of this decrease in 

 activity, the author can only conclude that it is due 

 to the substrate and product of reaction, hydrogen 

 peroxide and oxygen ; and the rate of decrease is 

 approximately proportional to the principal reaction. 

 The decrease in activity is not to be attributed to 

 change in concentration of hydrogen ions. It has 

 already been found that in a very dilute solution of 

 hydrogen peroxide and a comparatively concentrated 

 solution of catalase the relative activity increases in 

 the first stage and then decreases gradually. This 

 behaviour may be attributed to the facts (i) that the 

 ordinary reaction would be carried out at a rate some- 

 what higher than that which is calculated according 

 to a first-order reaction ; (2) that the rate is retarded 

 with hydrogen peroxide and oxygen in ordinary cases ; 

 (3) that such effects are observed only in the course of 

 reaction in very diluted solutions, because the con- 

 centration of both the substrate and the product are 

 very small, i.e. the velocity constant has a maximum 

 value ; and (4) that the retardation proceeds with the 

 measurable velocity, which is approximately propor- 

 tional to the principal reaction. 



The Rotary Club of London, composed of about 

 three hundred members, each representing a different 

 trade or profession, and connected with twenty-five 

 other rotary clubs in other parts of the British Isles, 

 has unde&taken the urgent and important work of 

 endeavouring to find posts for demobilised men out of 

 employment We are asked to direct attention to 

 this most praiseworthy task and have much pleasure 

 in doing so. Thousands of capable officers and men 

 who were on active service during the war are 

 now seeking employment, and particulars of 

 vacancies of any kind may usefully be sent to Mr. 

 Edward Unwin, jun., at the " Rotary Room,"' 

 Horrex's Hotel, Norfolk Street, Strand, London, 



W.C.2. 



Mr. H. Martin Leake, Director of Agriculture, 

 United Provinces, India, is publishing through 

 Messrs. W. Heffer and Sons, Ltd., "The Bases of 

 Agricultural Practice and Economics in the United 

 Provinces, India," in which the history of agriculture 

 is traced; the fundamental facts of agricultural prac- 

 tice and economics are described ; the lines upon which 

 agricultural practice is likely to develop are brought 

 out, and emphasis is laid upon the fact that recent 

 advances in scientific knowledge have made it possible 

 for directed, as opposed to undirected or empirical, 

 methods to be employed. It further indicates the 

 weaknesses of the present economic system, and 

 develops the idea of co-partnership in the land between 

 landlord, tenant, and Government. 



Messrs. Dulau and Co., Ltd., 34 Margaret Street, 

 W.I, have just issued a catalogue {No. 82) of an 

 important botanical library recently purchased by 

 them, the volumes in which are now offered separately. 

 The works listed number ^593, and many are scarce. 

 The catalogue is one likely to interest all students 

 of botany, and copies may be had of Messrs. Dulau 

 upon application. 



