18 
centage of albuminous compounds for air-dried crops are given as 
follows: 
Cellulose | Albumi- Cellulose | Albumi- 
Plant. (dried at | noids (air Plant. (dried at | noids (air 
212°). dried). 212°). dried). 
Potato tubers: -....--.--- ae Oe eer Beamsesss sete see Seen epee a oes 24-41 
Wheat kernels----...---- 3.0 11-20 || Red clover hay---------- 34.0 12-20 
Maize kernels___...___-.- 5.5 LO=167) een 0 hiya | 23.0) Sesees sete 
Barley kernels. __--.-...- 8.0 12-16 || Oat straw --.------.------ | 400) |S ae 
Ontikernelsepeesee = eee 10.3 11-17 || Wheat straw -_...._---.- 48.0 3-4 
Buckwheat kernels- ----- 15.0 10--14 || Rye straw---...--------- 54.0 3- 4 
doy Ue os mar F Ma em Sena | LAE 2 it oe 22-36 
This crude chemical analysis of the walls and of the contents of the 
crushed cells tells us nothing of the life that had previously resided 
in the uncrushed organisms, but prepares us for the statement that 
the development of a plant imphes a great amount of work done 
among the molecules in rearranging them into the places where 
they are needed. These molecules come from the simpler atoms in 
the soil, the air, and the rain water, but the force and energy that 
does the work of building them up comes, so far as we know, from the 
sunshine. It is a case of the transformation of energy. Within the 
cells of a plant the molecular energy, or the so-called “ radiant 
energy,” that would otherwise produce the phenomena of heat and 
light is transformed into chemical activity and produces the new 
molecular compounds that we use as food. We and other animals 
can not produce these compounds in our own bodies, but we can utilize 
them if they are not injured in the process of cooking. 
GENERAL RELATIONS OF THE SEED AND PLANT TO THE AIR 
AND THE SOIL. 
RESPIRATION. 
It is known that in the act of germination the seed absorbs oxygen 
from the air contained in the interstices of the soil and that very few 
seeds will germinate when the soil and the water are deprived of air 
or free oxygen. 
As to the full-grown plant, it is commonly said to absorb carbonic- 
acid gas from the air through its leaves and to exhale oxygen. The 
investigations of Moisson tend to modify this statement and show 
that at low temperatures there is more oxygen absorbed than there 
is earbonic-acid gas produced, while at high temperatures the reverse 
is true. For each plant there is a certain temperature at which each 
volume of carbonic-acid gas absorbed is replaced by an equal volume 
of oxygen exhaled by the leaves. Thus in the case of the Pinus 
pinaster for every 100 volumes of oxygen absorbed there are 50 
volumes of carbonic-acid gas exhaled at 0° C. temperature, but 77 
volumes at 13° C. and 114 volumes at 40° C. 
