Albany and Rensselear Horticultural Society. 375 
original fibres are again surrendered to the soil in their turn, to 
enter into new relations, and to serve new purposes in the physio- 
logical economy of another generation. The carbonic acid gas 
eliminated in decay is not produced in vain. When the rootlets 
of the young grasses are feeble, while the growing stem and leaves 
draw much upon them, the genial rain descending dissolves this 
gas, and supplies it to the spongioles of the roots in a liquid form, 
to be then carried up into the vegetable system, and there de- 
composed. So far for the chemistry of death in the sod. How 
little do we prize the purifying influence of our green fields! How 
little value the myriads of minute laboratories in the greensward, 
which, busy all the day long, drink up the detrimental carbonic 
acid gas of our impoisoned air, and pour out in return, volume for 
volume, invisible fountains of purest oxygen! Such, humble as 
they are, is their high vocation, so far as it directly relates to 
man. That fatal gas which he and his manufactures, and his 
humbler relatives in the zoological scheme — animals, birds, and 
the almost invisible insect — alike combine to produce, the cheerful 
sward seeds upon', gladly appropriates, makes into wood, turns 
into leaves and stems, and, more useful still, converts into health- 
sustaining food for man and beast. • During the shades of night 
the grass lands, in common with the rest of vegetation, evolve 
carbonic acid; but it has been satisfactorily demonstrated that the 
preponderance is incomparably in favor of the oxygen evolution 
during the day. 
We have spoken of the tender blades which crown our sod as 
forming food. The chemical analysis effected by Sir H. Davy 
shows that the following principles in the grasses are those by the 
possession of which it is adapted for this end. Their remarkable 
simplicity will not fail to be observed: mucilage, sugar, bitter 
extractive matter, a substance analogous to albumen, and various 
saline ingredients. Let this suffice for the history of a sod. The 
desire has been to exhibit, however imperfectly, the rich and 
varied amount of interest and instruction which may be made to 
flow out of the contemplation of one of the commonest objects in 
nature. 
ALBANY AND RENSSELAER HORTICULTURAL SOCIETY. 
The second meeting of this society, for the present year, was 
held at the court house in the city of Troy, on the 12th ult. The 
President, Joel Rathbone, in the chair. 
The exhibition of fruits, flowers and vegetables was fully equal, 
if not superior, to either of the former exhibitions; and the show 
was such, in all respects, as to satisfy the friends of the society 
