law: Indian Trusts Act, 1882 
  40. Power to vary investments 
  A trustee may, at his discretion, call in any trust-property
  
  invested in any security and invest the same on any of the securities mentioned
  
  or referred to in section 20, and from time to time vary any such investments
  
  for others of the same nature:
  PROVIDED  that, where there is a person competent to
  
  contract and entitled at the time to receive the income of the trust property
  
  for his life, or for any greater estate, no such change of investment shall be
  
  made without his consent in writing.