AsyncAppender "blocking" property

[Adam Mitchell]

I'm trying to disable blocking in the AsyncAppender, but get this message on
init:

log4j:WARN No such property [blocking] in org.apache.log4j.AsyncAppender.

Can the blocking property be configured from log4j.xml?  Here's my relevant
config:

    <appender name="ASYNC" class="org.apache.log4j.AsyncAppender">
        <param name="Blocking" value="false"/>
        <appender-ref ref="ILM"/>
    </appender>

I've tried "Blocking" and "blocking" with the same results.