# Elementary, my dear Watson!

"The expression on your face, Watson, coupled with the sheet of foolscap in your hand, leads me to deduce that you are quite puzzled about something."

"Indeed I am, Holmes. Perhaps you can make head or tail of it; I have got nowhere so far. Here..."

"Thank you. Oh, this is quite clear. The answers to the questions at the bottom are..."

What?

Here is the text on the sheet of foolscap; it is only the text that is relevant, not the handwriting, color, spacing, et cetera.

VALID WORDS     INVALID WORDS

BEAT            STRIKE
CYLINDER        TUBE
TICS            TWITCHES
BOGS            MARSHES
COPPER          PENNY
SILVER          GOLD
ALIASES         NICKNAMES

1. IS 'VALID' A VALID OR INVALID WORD?

2. WHAT IS THE CRITERION FOR VALIDITY?

• Note this is actually a duplicate of sorts; this puzzle already used roughly this criterion. – Rubio Apr 28 '17 at 19:16
• It was not suggested as a possible duplicate while I was entering it. – Jeff Zeitlin Apr 28 '17 at 19:30
• That's not a particularly reliable way to look for duplicates :) Just so you know, we have a whole set of puzzles that follow the theme of "what rule distinguishes These Words from These Other Words" - you might be interested in checking some of 'em out. See e.g. What Is a Unionized Word™?, the latest in the series, which has links at the top to find the rest. – Rubio Apr 28 '17 at 19:38

## 1 Answer

I think

VALID words are the ones in which all the letters or pair of letters are chemical element codes

BEAT - BE+AT
CYLINDER - C+Y+LI+ND+ER
TICS - TI+CS
BOGS - B+OG+S
COPPER - CO+P+P+ER
SILVER - SI+LV+ER ALIASES - AL+I+AS+ES

While the INVALID ones do not have this property.

The title Elementary clues towards looking at the element codes.. Complete list of codes!