LABORATORY METHODS OF INQUIRY 35 



that Englishmen are on the average fairer than negroes and taller 

 than African pigmies, and so on as regards millions of facts. 



62. On the other hand, we cannot without the experiment of 

 weighing discover the precise weight of a stag, nor without biometry 

 the exact degree in which Englishmen are on the average fairer 

 than negroes and taller than pigmies. In a sense, of course, the 

 statement, for example, that Englishmen are on the average exactly 

 so many inches and fractions of an inch taller than pigmies is more 

 precise than the bare statement that they are taller ; but only in a 

 sense. For the one statement is not truer, but only contains more 

 of truth than the other. That is, it is more detailed. Obviously, 

 whether or not the additional details are needed in any given 

 inquiry, depends on circumstances. They are not always needed. 



63. Beyond question, biological facts discovered in the labora- 

 tory are often very valuable as valuable as any other verified 

 facts, and on particular occasions more valuable because designedly 

 discovered with a view to fill gaps which prevent the linking 

 together of facts already known. There is, however, nothing 

 especially magical, scientific, or accurate in data obscured to our 

 senses till revealed by a laboratory inquiry. Such an inquiry can 

 do no more than render them as patent, but no more patent than 

 the majority of facts on which our knowledge of living beings is 

 based. The latter class of facts, indeed, are usually more capable 

 of easy verification than any discovered in the laboratory. In 

 noting them we have only to guard against errors of observa- 

 tion, not also against errors in experimenting. If the reader will 

 think over the evidence on which I shall draw for the purposes of 

 the present volume, I believe he will conclude that, if any of it 

 bears a doubtful aspect to his mind, it is that large mass which has 

 been furnished by laboratory inquiry ; for, while some of the 

 latter is controverted, and all of it must be accepted by most 

 people at second hand, nearly all the rest is indisputably true, as 

 he will know from his own experience of life. 



64. Sometimes it is said that we must make biology an exact 

 science by imitating the methods of physicists and chemists by 

 which is meant that we must experiment, or compile statistics. It 

 is right that we should do both when necessary ; but, plainly, 

 physics and chemistry are exact sciences, not because the facts on 

 which they are based are obscured and have to be laboriously dis- 

 covered by laboratory methods, but because they deal with data 

 that are capable of being exactly measured, and because physicists 

 and chemists have had both the means and the will to test their 



