528 



NA TURE 



[April 5, 1894 



reactions, to which the name "ptomaines " was given, 

 and which were carefully investigated by Brieger. When 

 Hankin discovered an albumose amongst the metabolic 

 pi oducts of anthrax bacilli, the ptomaines were regarded 

 with suspicion, and toxalbumins in the form of albumoses, 

 peptones, globulins, separated from artificial cultures of 

 pathogenic bacteria, and pronounced to be the true toxins. 

 The fact that in snake venom and some vegetable 

 poisons, such as abrin and ricin, similar toxalbumins 

 were obtained, lent still further interest to the whole 

 question, and our path seemed perfectly clear. Duclaux, 

 of Paris, at all times raised objections of great weight 

 against this conception of toxalbumins, and the recent 

 works of Buchner, Sidney Martin, and others tend to show 

 that the toxins of most pathogenic micro-organisms are 

 ferment-like bodies, not reacting as ordinary albumoses, 

 peptones, globulins, or albumins when the germs are 

 grown in non-albuminous substances. 



Dr. Jorgensen's work discusses the phenomena of 

 alcoholic fermentation only and especially as applied to 

 the brewing of beer, and does not give a general account 

 of fermentation in all its aspects, physiological or patho- 

 logical, as we had hoped from the title of the book. The 

 Danish savant is, however, hardly responsible for the 

 slight disappointment which we experienced on finding 

 that the scope of the book, which numbers over 250 

 pages, is limited to alcoholic fermentation, for the German 

 word " Gahrung" is generally used to signify this special 

 kind of fermentation. Though this book appeals in the 

 first instance to scientific brewers, and none the less to 

 practical ones, it contains much of special interest to the 

 biologist, bacteriologist, and chemist. The greatest 

 merit is the collection and summary of Hansen's 

 work on yeasts, and we must be grateful to the 

 translators for having given us the results of 

 the patient and laborious investigations made at the 

 Carlsberg Laboratory in an English rendering. Hansen 

 cleared the hopeless confusion existing regarding the 

 saccharomycetes by finding methods for obtaining pure 

 cultures and separating and distinguishing various allied 

 forms which, though hitherto included under the same 

 name, were mere impurities. He rendered a great service 

 to botany and biology by giving an accurate description 

 of the sporulation of these organisms, their various 

 forms of spores, and their germination, facts which 

 enabled him to differentiate between various groups of 

 saccharomycetes. Amongst the latter only organisms 

 are found capable of rapidly and vigorously fermenting 

 maltose, and the yeasts for breweries and distilleries must 

 therefore be sought among them, and a suitable species 

 must always be selected for each particular kind of beer. 

 Hansen studied also and discovered groups of wild 

 yeasts which produce diseases in beer, such as bitter 

 taste and turbidity, and he showed that these unwelcome 

 guests are capable of doing harm only when introduced 

 into the wort at the commencement of fermentation. He 

 has also pointed out ways and means to avoid and pre- 

 vent disease in beer. Dr. Jorgensen carefully describes 

 the various species and varieties of saccharomycetes and 

 torulse, and a point of special interest is the tendency of 

 many among them to form mycelia or pro-mycelia, a 

 tendency which by Klein and others has also been ob- 

 served in schizomycetes, such as diphtheria,'tubercle, and 

 NO. 1275, VOL. 49] 



anthrax bacilli. For industrial purposes absolutely pure 

 and carefully selected yeast cultures should be used for 

 brewing. This is already done by many breweries on 

 the continent and in America. In England, however, 

 we are slow in applying scientific research to industrial 

 pursuits, and though a number of breweries already use 

 Hansen's system, it can hardly be said that it has re- 

 ceived the attention it deserves, and chance, tradition, 

 and blind empiricism still govern too much the manufac- 

 ture of beer in England. As Prof. P. Frankland says: 

 " Scientific accuracy and the certainty of success can 

 only be introduced into the industry of brewing with a 

 due appreciation of these brilliant researches." 



Dr. Jorgensen has treated his subject in a thoroughly 

 scientific and withal clear and concise manner, which 

 suffers but little, if at all, from the translation. To brewers 

 and those interested in the mycotic chemistry of brewing, 

 the book will be welcome, and to those who are not able to 

 read the works of Hansen in the language in which they 

 have b3en written, it will be invaluable. We hope that 

 this work will assist in banishing empiricism from the 

 English systems of beer fermentation. The general 

 application of Hansen's method is merely a question of 

 time. A. A. Kanthack. 



OUR BOOK SHELF. 



A Year aniojif^st the Persiaijs. Impressions as to the 

 Lije, Character, and IJioiii^ht of the People of Persia, 

 received during:; tzvelve months' residence in that country 

 in the years 1S87-8. By Edward G. Browne, M.A., M.B., 

 Lecturer in Persian to the University of Cambridge 

 (London: A and C. Black, 1893.) 



Mr. Br(3WNE's studies lie in the realms of metaphysics 

 and linguistics, subjects which appeal readily to the 

 cultured Persians of the cities. Hence he has obtained 

 more insight into the intellectual side of Persian life than 

 falls to the lot of most foreigners visiting the Shah's 

 dominions. His sympathies are wide, and his tact con- 

 siderable, for he succeeded in winning the confidence of 

 the persecuted Babis and down-trodden Gucbres of 

 Shiraz and Yezd without incurring the enmity of the 

 official classes. The story of these people and their be- 

 liefs is admirably told, but from its nature it lies outside 

 the scope of critical consideration in this journal. 

 Amongst the Guebres or Zoroastrians of Yezd Mr. 

 Browne recognised the most perfect representatives of 

 the ancient Persian race, the physical type being kept 

 pure by the unceasing persecution to which the sect has 

 been subjected since the commencement of Moham- 

 medan supremacy. These people are in constant com- 

 munication with their kinsmen the well-to-do Parsis of 

 Bombay, who occasionally revisit the country of their 

 origin. The glimpses of the habits and customs of 

 Persian life and thought are singularly vivid, and although 

 the author rather avoids mere topographical detail, his 

 brief sketches of the cities in which he sojourned are 

 powerfully drawn and strikingly accurate. The great 

 want of the country appears to be irrigation, which is 

 carried on at present very partially and in a wasteful 

 manner. Near Kashan a stream was found carefully 

 daiTimed at intervals to cause the water to overflow the 

 bank and trickle into the channel below heavily charged 

 with mud, the reason assigned being that muddy water 

 evaporates less rapidly than clear. 



While the book is generally free from error, we note a 

 slip, hardly to be expected of a Cambridge graduate, on , 

 p. 463, where he speaks of a hole a yard square, when the 



