“The letter which Chester received was in a square, white envelope,” said Dallas. “I noticed that as soon as he showed it to me. And,” she went on, with a puzzled frown, “that’s something which I can’t understand at all. I know that it sometimes happens that in a box of colored stationery a white envelope will get mixed with the tinted ones, but I am ready to take oath that the envelope in which I inclosed Chester’s letter was pink. If it wasn’t so perfectly ridiculous I should be inclined to believe that it must have changed color while in the mail.”
“Wait a minute!” exclaimed Owen, an inspiration coming to him. “I think I’ve got the answer. This en[Pg 44]velope was exactly the same shape and design as the rest in the box, wasn’t it, Dallas?”
“Yes; exactly the same as the others, except that it was white instead of pink.”
“And it appeared to you to be pink?”
“Yes; and I am not color blind—if that is what you are going to imply,” replied Dallas, mildly indignant.
“I’m not quite so sure of that,” said Owen, with a smile. “I’ll grant that you are not color blind under ordinary conditions, but these were not ordinary conditions.”
“What do you mean by that?”
“It was a dark afternoon when you addressed that envelope, and the electric light over your desk at the office was turned on, wasn’t it?”
The girl nodded. “Yes, that’s so; but still——”
“And the electric globe over your desk throws such a strong light that you have a piece of paper around it to shade it, haven’t you, Dallas? A piece of red paper; I noticed it the other day.”