BORIC ACID AND BORAX. 31 



by the great majority of our people that added preservatives are 

 always injurious and in many instances poisonous. But even when 

 personal bias, weight of authority, and public opinion are eliminated 

 from the problem it is still a most difficult one. So many elements 

 enter into its study, so many conditions difficult to control, so many 

 idiosyncrasies are to be reckoned with, so many external causes influen- 

 cing health which are beyond control, that it is difficult in many cases 

 to decide, where variations are noticed, as to the exact or even appar- 

 ent cause which has produced them. 



The problem, therefore, has been attacked with a full knowledge of 

 its difficulty and with the desire to be conservative and free from 

 dogmatism. It would probably be better if all the detailed data which 

 have been secured could be printed in connection with this discussion, 

 so that the critical reader might be able in every instance to refer to 

 the original figures. Enormous space, however, would be occupied 

 by the data, and the fact that in most cases they would be of little use 

 in detail has led to the decision to publish only such detail as may be 

 necessary to point out the way in which the general data have been 

 obtained. If, as may appear further on, all points of the problem 

 have not been elucidated, the failure has not arisen either from lack 

 of desire or from want of industry in the conduct of the experiment. 

 It is to be attributed, rather, to the limitations placed upon the observ- 

 ers, either by lack of experience or by lack of knowledge, as to the 

 best way in which to classify, digest, and study the data at their dis- 

 position. A serious attempt has been made to present these data in 

 their full significance, and in no case has any tampering therewith been 

 counseled, desired, or permitted. The unfortunate fact that many of 

 the data are contradictory must be accepted without question. As the 

 judge and the jury, in the light of contradictory evidence, seek to 

 decide which is the more trustworthy, so have the data herein con- 

 tained been interpreted with a view, if possible, to giving the greater 

 weight to those which deserve the greater credit. 



