Question:
Which position did William Dougal Christie hold in Sep, 1847?

Context:
 William Dougal Christie holds the position of ambassador of the United Kingdom to Brazil from Jan, 1859 to Jan, 1863. 
 William Dougal Christie holds the position of Member of the 15th Parliament of the United Kingdom from Jul, 1847 to Dec, 1847. 
 William Dougal Christie holds the position of Member of the 14th Parliament of the United Kingdom from Apr, 1842 to Jul, 1847. 
 William Dougal Christie holds the position of ambassador of the United Kingdom to Argentina from Jan, 1854 to Jan, 1859.

Answer:
Member of the 15th Parliament of the United Kingdom