title: Extract "words" from a string
body: <p>I have a table with 153 rows by 9 columns. My interest is the character string in the first column, I want to extract the fourth word and create a new list from this fourth word, this list will be 153 rows, 1 column.</p>
  
  <p>An example of the first two rows of column 1 of this database table:</p>
  
  <pre><code>[1] Resistance_Test DevID (Ohms) 428
  [2] Diode_Test SUBLo (V) 353
  </code></pre>
  
  <p>"Words" are separated by spaces, so the fourth word of the first row is "428" and the fourth word of the second row is "353". How can I create a new list containing the fourth word of all 153 rows? </p>