Can we draw the following hypothesis from the context? 

Context:

Gray and I were sitting together at the far end of the block house , to be out of earshot of our officers consulting ; and Gray took his pipe out of his mouth and fairly forgot to put it back again , so thunder-struck he was at this occurrence .<br>`` Why , in the name of Davy Jones , '' said he , `` is Dr. Livesey mad ? ''<br>`` Why no , '' says I. `` He 's about the last of this crew for that , I take it . ''<br>`` Well , shipmate , '' said Gray , `` mad he may not be ; but if HE 'S not , you mark my words , I am . ''

Hypothesis: Gray was older than the narrator.
It's impossible to say