THE BIOLOGY OF DAILY LIFE. 119 



England," have to be rejected simply on the ground 

 that they are not so honest as they seem. They are like 

 the " honest lago," and when most trusted are apt to 

 betray the heart that trusts in them. The microscope 

 detects, under their bluff friendliness, the deceitful leer 

 of the leucocyte. 



Wide as is my hospitality, at least in intention, I 

 should not care to sit at table with my own destined 

 hangman, " not if I know it." 



But still more strictly are we warned against all 

 chemical foods, and every man or woman who cares 

 for bodily well-being should take the words of a cele- 

 brated American Chemist, who (with that instinct which 

 so often in the case of true men of science seems to 

 anticipate the deductions of strict science) has given 

 this emphatic opinion : 



" I cannot but think, although it may be a 

 prejudice, that chemicals had better be kept out 

 of the kitchen/' * 



It is the Biologist and not the Chemist who gives 

 the full reason. To the Chemist it is a " prejudice." 

 He sees that Nature is very exact and exacting. 

 That the smallest particle of matter out of place will 

 spoil his experiment. Scrupulous cleanliness of flask 

 and beaker, and tube and retort, and exactness of 

 weighing, for a true chemical balance, will weigh the 

 " small dust" of the best common balances, are his 

 familiar requirements. 



* Professor J. Cooke, junr. The full quotation is as follows : 

 " When soda and cream of tartar are used in making bread, this 

 salt (" Eochelle salt") remains in the loaf. The amount formed 

 is too small to be injurious, but I cannot but think, although it 

 may be a prejudice, that chemicals had better be kept out of the 

 kitchen." The New Chemistry, p. 148. 



