Show rough leaved trees unsuitable for city smooth leaved trees say experts are the only ones that can live on city boulevards in this day of automobiles only th those ose whose foliage Is based was ed by rain and du dusted sted olt off by the breeze they believe will thrive they have found that th the rough leaves of chestnuts and similar trees have their breathing pores burned by sulp sulphuric burle field acid sulphurous dust says professor de mor lalue ot of the french agricultural institute Is produced by the exhaust from automobiles this he be says becomes sulphuric acid in humid air and works into the pores of the leaves I 1 smooth leaves would be washed clean by occasional rains or the dust would be blown off by winds before it could damage the trees |