236 O. W. HOLMES 



be found to profess a disbelief in contagion, and they 

 are very few compared with those who think differently, 

 is it quite clear that the)'- formed their opinions on a 

 view of all the facts, or is it not apparent that they re- 

 lied mostly on their own solitary experience? Still further, 

 of those whose names are quoted, is it not true that scarcely 

 a single one could, by any possibility, have known the half 

 or the tenth of the facts bearing on the subject which have 

 reached such a frightful amount within the last few years? 

 Again, as to the utility of negative facts, as we may briefly 

 call them, instances, namely, in which exposure has not 

 been followed by disease, although, like other truths, they 

 may be worth knowing, I do not see that they are like 

 to shed any important light upon the subject before us. 

 Every such instance requires a good deal of circumstantial 

 explanation before it can be accepted. It is not enough that 

 a practitioner should have had a single case of puerperal 

 fever not followed by others. It must be known whether 

 he attended others while this case was in progress, whether 

 he went directly from one chamber to others, whether he 

 took any, and what, precautions. It is important to know that 

 several women were exposed to infection derived from the 

 patient, so that allowance may be made for want of predis- 

 position. Now, if of negative facts so sifted there could be 

 accumulated a hundred for every one plain instance of 

 communication here recorded, I trust it need not be said 

 that we are bound to guard and watch over the hundredth 

 tenant of our fold, though the ninety and nine may be sure 

 of escaping the wolf at its entrance. If any one is disposed, 

 then, to take a hundred instances of lives, endangered or 

 sacrificed out of those I have mentioned, and make it reason- 

 ably clear that within a similar time and compass ten 

 thousand escaped the same exposure, I shall thank him for 

 his industry, but I must be permitted to hold to my own 

 practical conclusions, and beg him to adopt or at least to 

 examine them also. Children that walk in calico before 

 open fires are not always burned to death; the instances to 

 the contrary may be worth recording; but by no means if 

 they are to be used as arguments against woollen frocks and 

 high fenders. 



