NA TURE 



853 



CONTENTS. 



The Problems of Pasteurisation .... 853 

 Facts and Fancies in Modern Anthropology. By 



Sir Arthur Keith, F.R.S 854 



The Orders of Insects. By A. D. I. . . . 857 



Photographic Science. By T. S. P. • . • 858 



Our Bookshelf 859 



Letters to the Editor : — 



Some New Commensals in the Plymouth District. 



{nhtsirated.)—Dv. J. H. Orton . . .861 



Conductivities of Aqueous Salt Solutions. — Prof. 



A. J. Allmand and L. Nickels . . . 862 

 The London Fogs of November 25-27, 1923. ( With 



Diagram.) Dr. J. S. Owens .... 862 

 Upper Air Conditions after a Line-Squall. ( With 



Diagram.)— m. A. Giblett . • . .863 

 Experiments on Cioita intesiinalis. — J. T. Cunning- 

 ham 864 



Mrs. Hertha Ayrton.— Dr. H. H. Mills; Prof. 



Henry E. Armstrong, F.R.S. . 865 



Zoological Bibliography. — ^T. Sheppard • . 865 

 Micelles and Colloidal Ions. — Prof. James W. 



McBain, F.R.S 865 



Biography of Richard A. Proctor. — Mrs. Proctor- 

 Smyth and Miss Mary Proctor . . . 865 

 The Treatment of Disease by Artificial Light • • 866 

 Some Aspects of the Physical Chemistry of Inter- 

 faces. Hy Prof. F. G. Donnan, C.B.E., F.R.S. 867 

 Obituary : — 



Dr. Alexander Gleichen. By Dr. James Weir 



French ........ 870 



Mr. G. D. Maynard. By M. G. . .871 



Mr. T. F. Cheeseman. By B. D. J. .871 



Current Topics and Events ..... 872 



Our Astronomical Column . . . . .875 



Research Items ....... 876 



Loud-speaking Telephones ..... S78 



Congress of the French Society of Chemical Industry. 



By Prof. Henry E. Armstrong, F.R.S. . . 879 



The Present Position of the Ergot Problem . . 880 

 Clothes Moths and their Control. By Dr. A. D. 



Imms ......... 880 



Science in Agriculture . . . . .881 



The Quantum Equivalent in Photo-electric Conduction 882 

 Early Methods of Oil Painting. By Prof. A. P. 



Laurie ......... 882 



The Geological Society of China. By Prof. J. W. 



Gregory, F.R S. 883 



University and Educational Intelligence . . 883 



Societies and Academies .... . 885 



Official Publications Received . ... 888 



Diary of Societies ....... 888 



Editorial and Publishing Ofiices : 



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NO. 2824, VOL. I 12] 



The Problems of Pasteurisation. 



IN the recent National Milk Conference convened by 

 the National Clean Milk Society at the Guildhall, 

 London, the problems of pasteurisation which formed 

 the subject of articles in Nature for January 27 and 

 February 3 of this year were discussed. Pending the 

 publication of fuller reports, it would appear that not 

 much additional knowledge has been acquired from 

 experimental or other investigations since those articles 

 appeared. Opinion in the Conference differed widely 

 as to the wisdom of pasteurisation of cows' milk under 

 present conditions. Thus, Prof. H. E. Armstrong 

 maintained that the Ministry of Agriculture and the 

 Ministry of Health were working against the public 

 interest by " patting pasteurisation on the back," 

 while not forcing those who heated milk to tell the 

 public what they had done with it. With the emphasis 

 laid in this statement on the desirability of making it 

 compulsory to declare the fact of pasteurisation and 

 the temperature at which it is undertaken, when com- 

 mercially practised, all hygienists will agree ; but they 

 would scarcely agree with the possible inference that 

 regulated pasteurisation of milk is an evil. Other 

 hygienists, like Profs. J. M. Beattie and H. R. Kenwood, 

 favoured the practice of pasteurisation, the first named 

 summarising his views in the words that pasteurisa- 

 tion, properly carried out, at a constant temperature 

 somewhat higher than that at present in use, would 

 bring about the destruction not only of tubercle 

 bacilli but also of all other important pathogenic 

 organisms. 



The problem of pure milk is con^plicated by the 

 desirability of cheap milk, and of increase in the per 

 capita consumption of milk from about a quarter of a 

 pint daily to at least three times this amount. Clean 

 milk is necessarily expensive. The dangers from 

 relatively uncleanly milk are reduced to a minimum by 

 efficient pasteurisation. At the same time, improved 

 sanitation of milk is extremely important even when 

 pasteurisation is contemplated ; while conversely, even 

 clean milk produced under rigid conditions may 

 occasionally cause disease unless it is pasteurised. 



Neither method of approach to improvement can be 

 neglected. Dairy and milk sanitation is important ; 

 but, for the efficient protection of the masses of popula- 

 tion living in large cities, pasteurisation is necessary. 

 This pasteurisation must, however, be efficient, and to be 

 efficient it must be controlled and always declared, in 

 order that the circumstances in which pasteurisation 

 has been carried out may be inspected. Further- 

 more, more experimental work is needed on the 

 various processes of pasteurisation as to their relative 

 efficiency. 



