344 



NATURE 



[May u, 1911 



importance in practical work, is excellent. The illus- 

 trations of gas-fired kilns, on pp. 81-4, should prove 

 of great value to the English manufacturer, who, 

 so far, has made little use of continental improve- 

 ments in methods of firing. 



The chapter dealing with pyromctry and pyroscopes 

 is also well done, and the discussion of the value of 

 the "Seger" cone is singularly clear and accurate. 



We can cordially recommend the work to all who 

 are interested, either as manufacturers or as users 

 of refractory materials, and it would be a still greater 

 pleasure to note the appearance of an English work 

 «8 comprehensive in scope and plan. 



William Burton. 



BACTERIOLOGY : GENERAL AND SPEaAL. 

 (i) Agricultural Bacteriology, Theoretical and Prac- 

 tical. By Prof. John Percival. Pp. x + 408. (Lon- 

 don : Duckworth and Co., 1910.) Price 7s. 6d. net. 



(2) A Text-Book of General Bacteriology. By Prof. 

 W. J. Frost and Prof. E. F. McCampbell. Pp. 

 xvii + 340. (New York: The Macmillan Co.; Lon- 

 don : Macmillan and Co., Ltd., 1910.) Price ys. 

 net. 



(3) Die Eisenhakterien. By Prof. Hans Molisch. 

 Pp. vi + 83. (Jena: Gustav Fischer, 1910.) Price 

 5 marks. 



(4) The Sources and Modes of Infection. By Dr. 

 C. V. Chapin. Pp. ix+399. (New York: John 

 Wiley and Sons ; London : Chapman and Hall, 

 Ltd., 1910.) Price 125. 6d. net. 



(i) \1^E have read this book with much interest. 

 ' « The plan of it is well conceived, and it 

 will serve not only as a useful text-book on agricul- 

 tural bacteriology, but also as an excellent introduc- 

 tion to general bacteriology for those who are non- 

 medical and do not wish to specialise in the medical 

 and pathological side of bacteriology. 



In the opening chapters a general account is given 

 of the bacteria, their physiology, morphology, and 

 classification, and the methods employed in isolating, 

 cultivating, and studying them. Fermentation and 

 enzyme action are then briefly discussed, including 

 putrefaction. Next an excellent account is given of 

 the bacteriology of soil, of nitrification and denitrifica- 

 tion, and of the fixation of nitrogen, and, finally, the 

 bacteriology of manure, milk, cream, butter, and 

 cheese is dealt with. Considerable space is rightly 

 devoted to milk and milk products, and the subjects 

 of the sources of bacteria in milk, the fermentations 

 occurring in milk, the filtration, cooling, pasteurisa- 

 tion, and sterilisation of milk, milk and its relation 

 to disease, millc standards, cream and cream ripen- 

 ing, the bacterial content, flavour, and defects of 

 butter, and the ripening of cheese are adequately 

 described. A final chapter is devoted to the yeasts 

 and moulds. Throughout the book series of excellent 

 practical exercises for the student to work out are 

 attached to all the sections. A few errors appear 

 which will need correcting in a future edition. The 

 B. lactis acrogenes is described on p. 10 as Gram posi- 

 tive, on p. 275 it is correctly stated to be Gram nega- 

 No. 2167, VOL. 86] 



tive; on pp. 46-7, dealing with the neutralisation oj 

 culture media, it is stated that most bacteria grow 

 best when the medium contains 1 per cent, of fre< 

 normal acid ; this, however, is true only when phenol - 

 phth.iloin is used as an indicator, and such media ar< 

 alkaline to litmus. On pp. 96-8 the term "proi< 

 has been substituted several times for "proti 

 enzyme," entirely obscuring the meaning, and on 

 p. 1 16 '* nitrogen peroxide " appears in place of 

 "hydrogen peroxide." The book is clearly printed, 

 and contains a number of appropriate and utll- 

 executed illustrations. 



(2) The authors state that there is no »wi.v n. 

 English on the subject of general bacteriolc^y with 

 the exception of the translation of Fischer's "Vorles- 

 ungen," and have attempted to supply this want in 

 the present volume. On the whole the matter is pre- 

 sented in a readable and accurate form. The pre- 

 liminary chapters dealing with the history of bac- 

 teriology might have been somewhat extended with 

 advantage, and the omission of any mention of 

 Lister's work on the lactic fermentation seems un- 

 pardonable. The chapters summarising the structure 

 and composition of the bacterial cell and the 

 morphology and classification of the bacteria are ex- 

 cellent. The methods employed in bacteriology and 

 the general physiology of the bacteria are detailed at 

 some length, and in the final portion of the book the 

 biology of specialised groups of bacteria are briefly 

 described. We think the authors have succeeded in 

 their endeavour, and have produced a book which will 

 be of considerable service as a general introduction to 

 bacteriology. 



(3) This is a monograph on a group of micro- 

 organisms of considerable biological and practical in- 

 terest. A majority are thread- forming species, and 

 differ essentially in this respect, and also in the fact 

 that they form conidia, from the true bacteria. They 

 live in waters containing iron and have the capacity 

 of "attracting" the iron from its solution and of 

 depositing it around them as ferric hydroxide, which 

 stains them brownish-red in colour. Ulitmately the 

 organisms die, sink to the bottom of the water, and 

 cause the reddish-brown colour so often seen at the 

 bottom of streams and ponds. It has been suggested 

 that some of the ironore deposits have been formed 

 by the activity of " iron bacteria " living in the warm 

 waters of an ancient sea. They also cause rusting of 

 iron pipes and conduits and masses of their growth 

 sometimes mechanically obstruct the flow of 

 water in pipes. Prof. Molisch has collected in 

 this mofjograph the descriptions of the known 

 species; and with the attached bibliographies, illus- 

 trations, and plates, and details for their investiga- 

 tion, it forms a valuable survey of the group. 



(4) Although this subject is dealt with in works on 

 medicine, epidemiology, and bacteriology, and a 

 special work on it might be considered superfluous, 

 a perusal of its contents has convinced us that Dr. 

 Chapin has compiled an extremely useful summar>'. 

 The life of disease germs outside the body and the 

 conveyance of infection by contact, fomites, air, food 

 and drink, and insects, are fully considered. An im- 



