# File lib/envelope.rb, line 68
  def add(value)
    if value.kind_of? Envelope
      count = value.count
      if (count > 0)
        add value.high
        add value.low
        @count += (count-2)
      end
      self
    else
      begin
        @high = value if (@count == 0 || value > @high)
        @low = value if (@count == 0 || value < @low)
        @count += 1
        self
      rescue
        raise_no_compare value
      end
    end
  end