April 24, 1903.] 



SCIENCE. 



661 



ture. By William T. Sedgwick and 

 Charles-Edwaed a. Winslow. Memoirs 

 of the American Academy of Arts and Sci- 

 ences, A-ugust, 1902, Vol. XII., No. "V. 

 In these two papers by Professor Sedgwick 

 and Mr. Winslow — one dealing with their 

 personal experiments on the viability of 

 typhoid bacilli in ice, and the other a statis- 

 tical study of the determining factors of the 

 seasonal prevalence of typhoid in various 

 countries — we have presented to us an array 

 of interesting data, and especially is this true 

 of the second paper, in which the authors in 

 a painstaking manner have brought together, 

 correlated and made deductions from the 

 statistics of typhoid fever prevalence in many 

 and diverse localities. 



Constantly recurring outbreaks of typhoid 

 fever, even where rational precautions seem to 

 have been taken to insure the safety of the 

 public, and the never-failing seasonal rise and 

 fall due to conditions often not fully under- 

 stood, lend a peculiar interest to all trust- 

 worthy investigations bearing on these prob- 

 lems. Bacteriology has already aided in the 

 solution of many obscure problems of disease 

 and its dissemination. The etiology of vari- 

 ous diseases has been established beyond all 

 reasonable doubt and much information has 

 been gained in regard to the life histories of 

 many pathogenic bacteria. Yet, in the ma- 

 jority of instances, few, or at best unsatisfac- 

 tory data have been brought to light in regard 

 to the conditions of the life of these organisms 

 in nature, their habitat outside of the bodies 

 of infected animals and man, and the extent 

 of their distribution. Little is known posi- 

 tively of the conditions of their increase, sur- 

 vival or destruction in nature in the various 

 soils, water, ice, etc., and the effects of varia- 

 tions in temperature, especially those due to 

 seasonal changes on their life and growth. 

 The solution of these problems is of prime 

 importance, and its accomplishment must 

 eventually lead to the establishment of more 

 rational, stire and, it may be assumed, often 

 less irksome precautions for the protection of 

 the individual or community. The outcome 

 of such investigations tends in general toward 

 two principal ends : either to indicate danger 



where none was supposed to lurk, or to dissi- 

 pate the fear of a danger which does not exist. 



It may well be urged that few, if any, epi- 

 demics or even individual cases of typhoid 

 fever occur that could not have been prevented 

 by the intelligent application of knowledge at 

 our disposal, yet the fatal neglect of well- 

 known precautions by those in power, and the 

 criminal negligence or ignorance of those 

 upon whom we are forced to depend for much 

 of our water, ice, milk and food supply, leave 

 us little confidence in the bacterial purity of 

 these in their natural state. In this connec- 

 tion the experiments of the authors on the 

 viability of typhoid bacilli in ice have a special 

 interest even for the general reader, since the 

 facts presented and the conclusions reached 

 are, on the whole, of a reassuring nature. 

 Space will not permit of a review of these ex- 

 periments in detail. They follow very closely 

 in scope and character those carried out and 

 reported in 188Y by Dr. Prudden. Prudden's 

 work, although done many years ago and un- 

 der certain conditions which the present inves- 

 tigators have thought fit to eliminate, has been 

 largely confirmed and slightly extended. The 

 chief departure in technique consisted in the 

 substitution of freshly isolated typhoid bacilli 

 for typhoid bacilli that had been for some 

 time cultivated on artificial media, and the 

 gradual lowering of the temperature during 

 the process of cooling and freezing, so as to 

 avoid a too abrupt temperature change, since 

 Bordoni-Uffreduzzi claimed that on account of 

 the rapid changes of temperature in Prud- 

 den's experiment and his use of attenuated 

 cultures his results could only have a relative 

 worth, and the results accomplished under 

 natural conditions could not be directly de- 

 duced from them. 



As a result of the authors' experiments on 

 freezing typhoid bacilli in water and keeping 

 them at 0° C. or below, the conclusion is 

 drawn that less than one per cent, of the 

 typhoid germs present in water can survive 

 fourteen days of freezing, and that during 

 the first half hour of freezing a heavy re- 

 duction takes place amounting to perhaps fifty 

 per cent. ; after this ' the reduction proceeds 

 pretty regularly as a function of time.' 



