The scientific books of a deceased botanist, for the benefit of his widow, will be sold at private sale by the botanists of the Philadelphia Academy of Natural Sciences, during August and September next. As many botanists will visit Philadelphia during the meetings of the Scientific Associations in the last of August and first week in September, they will have a rare chance to supply themselves with good things. In the collection is Audubon's Birds. This is an extremely rare book to obtain. It is quoted in London catalogues at $1000 a copy.