1922.] 



Notices of Books. 



957 



NOTICES OF BOOKS. 



An Abstract of the Leg-islation in force in the British Empire, 

 deahng* with Plant Pests and Diseases up to the year 1920.— 

 (E. Marguei'ite Ralfs, B.A. London : Imperial Bureau of Entomology, 1921.) 

 As indicated by the title, this is a brief summary of the various orders 

 respecting fungus diseases and insect pests, chiefly in relation to their importa- 

 tion into the various countries with which it deals. It should prove of value 

 not only to the student of economic entomology and plant pathology, but also 

 to the exporter of plants who has hitherto had to rely largely on the information 

 contained in the post office guide, the original orders not being generally 

 available in this country. In some cases particulars are given of the measure* 

 in operation for dealing with pests already established. In the case of England 

 and Wales, however, the silver leaf, wart disease, onion smut and American 

 gooseberry mildew orders have been dismissed very briefly. Owing to the 

 frequent changes in phytopathological legislation, the abstract is soon likely 

 to become out of date, and it is hoped that timely revision may be found 

 possible — as a compendium of this kind should fill an undoubted need. If 

 arrangements could be made to include also abstracts of the legislation of 

 foreign countries as well as those within the British Empire, the publication 

 would be even more valuable, and its appearance annually would be fully 

 justified. 



Report on a Simple Steam Sterilizer.— (W. A. Hoy and R. 



Stenhouse Wilhams. London : Dairy Supply Co., Ltd.) From tests made 

 recently at the National Institute for Research in Dairying, University College,. 

 Reading, of a simple steam sterilizer designed for use on dairy farms where 

 no other source of steam is available, it appears that if effective sterilization 

 is to be obtained within a reasonable time, it must be carried out under certain 

 fixed conditions, namely — 



(1) The source of heat must be such that steam at 210°F issues from the 



outlet pipe within a limited time. In these experiments, in which 

 the largest vessel to be steamed was a 17-gallon milk churn^ 

 satisfactory results were not obtained until the source of heat, when 

 apphed to one gallon of water at 60°F., was sufficiently great ta 

 produce steam at 210°F. at the outlet pipe within ten minutes of 

 its first application. 



(2) The source of heat must maintain its intensity throughout the steaming, 

 (o) All milk utensils, including milk churns, should be covered while 



being steamed. 



(4) The steaming should be carried out in a place free from draughts. 



(5) An accurate thermometer is essential. 



The initial temperature of the room does not appear to affect the operation 

 appreciably. Successful results were obtained when the temperature of the 

 room and of the utensils was as low as 40°F. before steaming commenced. 



Conditions conducive to ineffective steaming. — (1) The experiments 

 showed that where an uncovered churn was being steamed and the windows 

 were opened, a fall in the recorded temperatures took place which was. 

 further accentuated by the draught caused. 



(2) It was shown that efficient steaming, within a reasonable time,, 

 was dependent on steam in sufficient volume and at a sufficiently high 

 temperature being produced within a time limit. 



The apparatus used in the experiments referred to in the report consisted 

 of an ordinary boiling pan (with steam jet) heated by means of two No. 1 

 Primus " Stoves, Roarer Pattern. 



