276 ANNUAL OF SCIENTIFIC DISCOVERY. 



if not, then the boiling must be continued for some time longer. 

 To bleach the skeletons, mix about a drachm of chloride of lime 

 with a pint of water, adding sufficient acetic acid to liberate the 

 chlorine. Steep the leaves in this till they are whitened (about 10 

 minutes), taking care not to let them stay in too long; otherwise 

 they are apt to "become brittle. Put them into clean water, and 

 float them out on pieces of paper. Lastly, remove them from the 

 paper before they are quite dry, and place them in a book or bo- 

 tanical press." HardwicMs Science- Gossip. 



GEOGRAPHY OF PLANTS. 



In an article on this subject by M. T. Lippincott, of New Jer- 

 sey, the following rules were given for determining the fitness of 

 districts in the United States for the growth of certain varieties of 

 wines : 



Those places which have a summer temperature of 65.6, a hot 

 month of 70, and a September of 60, will ripen Delaware, Clin- 

 ton, Perkins, lona, Logan, Israella, with other hardy varieties. 

 The temperature of their growing season corresponds to a mean 

 of 65 and upward, and an aggregate of heat of about 8,000 F. 



Those places which have a summer of 70, a hot month of 72, 

 and a September of 63, will ripen Concord, Hartford Prolific, 

 Diana, Creveling, etc. Their season of growth corresponds to a 

 mean of 67, and an aggregate of 8,500. 



The Isabella requires a summer of 72, a hot month of 73, and 

 a September of 65, and a mean during its growing season of 70, 

 and an aggregate of 10,000 of heat, etc., etc. 



OZONE PRODUCED BY PLANTS. 



Professor Daubeny, of Oxford, has contributed to the " Journal 

 of the Chemical Society," for January last, an interesting article, 

 giving the details of a series of careful experiments, which go to 

 prove that green foliage, in assimilating carbonic acid, water, etc., 

 liberates a part of the oxygen in the form of ozone. After his 

 experiments were made., Dr. Daubeny found that Kosmann, of 

 Strasburg, had reached the same conclusion, but through less re- 

 fined experiments. Referring to the first paper he ever communi- 

 cated to a scientific society, that published in the Philosophical 

 Transactions" for 1834, on the evolution of oxygen gas by plants 

 in the day-time, Dr. Daubeny concludes: "Should 1 now have 

 established, to the satisfaction of the scientific world, that these 

 same green parts of plants, at the very time they are emitting 

 oxygen, convert a portion of it into ozone, I might hope that these 

 researches of my later years will serve appropriately to wind up 

 those undertaken in my younger ones, by showing that vegetable 

 life acts as the appointed instrument for counteracting the inju- 

 rious effects of the animal creation upon the air we breathe, not 

 merely by restoring to it the oxygen which the latter had con- 

 sumed, but also by removing, through the agency of the ozone it 

 generates, those noxious effluvia which are engendered by the 

 various processes of putrefaction and decay," engendered, we 



