THE GARDENERS' CHRONICLE OF AMERICA. 
275 
must undergo chemical changes into some soluble com- 
pound. 
An indication has been given of the manner in which 
starch is brought into solution by the action of the 
enzyme, diastase. So many of the changes in organic 
matter are attributed to agencies of this kind that it may 
not be out of place to consider them a little more fully; 
An enzyme is a ferment which is unorganized or has no 
life. It is, however; a product of life. In fact, many of 
the changes which were supposed formerly to be due 
directly to the action of lower forms of life are really 
not brought about by the organisms themselves, but by 
unorganized or lifeless ferments which they secrete and 
which are called enzymes. The alcoholic fermentation re- 
sulting in the production of carbonic acid gas and which 
is exemplified by the action of yeast in bread-making, is 
not dependent upon the living yeast plant, but may be 
caused by an extract made from it. Likewise the enzyme 
diastase is extracted from sprouted barley : it is more 
commonly known as malt and is used in the process of 
beer-making for converting the starch into sugar. A 
number of enzymes in the human body have become 
fairly familiar to us such as diastase and ptyalin in the 
saliva, pepsin in the gastric juice and trypsin in the pan- 
creatic juice, but it may not be so generally recognized 
that similar ones, with similar functions to perform occur 
in plants and assist in changing the insoluble substances 
into compounds which may be utilized by the plant as 
food or be easilv transferred from one part to another. 
Many complex chemical changes take place within the 
plant ; in fact it may be looked upon as a laboratory in 
which one set of unstable compounds is decomposed to 
furnish ingredients from which other more stable com- 
pounds may be synthesized or built up. Enough has per- 
haps been said to impress one with the complexity of the 
changes going on within the plant ; it is not the purpose 
of this paper to compile in detail the views which are 
held concerning the multiplicity of changes, especially as 
these views frequently cannot from the very nature of 
the case be substantiated by experimental proof, but 
rather to throw a little light upon the subject in a more 
general way. Years of patient investigation by men who 
are satisfied to devote their lives to the study of these 
intricate questions and whose encouragement comes not 
from their fellowmen, who are too frequently unappre- 
ciative of their efforts, but from the thought that they are 
assisting in the search for truth, will be necessary before 
some of the questions will be answered. Some of the 
answers will very likely prove of immense economic value 
and will repay ten-fold all the expenses connected with 
obtaining them. Who could have predicted for example 
when the chemist Wahler succeeded half a century ago in 
producing a small amount of aluminum as a laboratory 
experiment by reducing its compounds with metallic 
sodium that we would today be using aluminum wire 
for conveying electric power from one locality to another. 
It required years of progress in technical chemistry re- 
sulting in a marked cheapening in the cost of producing 
metallic sodium before aluminum could be put upon the 
market at a sufficiently low price to replace copper in cer- 
tain instances, but the principle underlying its manufac- 
ture was discovered more than a half century ago. Some 
of the principles underlying plant-growth will some day 
be understood because of the beginnings which are being 
made today towards their discovery ; thus it is that one 
generation must start the work which another generation 
shall complete and apply practically. 
*Extracts from a lecture before the Rhode Island Horticultural Society. 
During the hot weather it is pretty hard to get a 
good crop of asters. In many places artificial water- 
ing can be resorted to, and when this is done it should 
be done thoroughly so that the water has a chance to 
soak down a foot or more. When the surface is suffi- 
ciently dry, stir it up with the hoe. It is surprising 
how much moisture can be retained by repeated 
hoeingrs. 
V-ww from the Terrace »* Front of Bartow Mansion, Pclham Bay, New York City, the Club House of the International 
Garden Club, During Its First Summer Flower Show. Spread on the Lawn Arc the Tents Which Housed the Indoor 
Foliage and Flowering Plants, Orchids, Cut Flozvers, Etc. Groups of MagnMcent Evergreen in Competition 
Are Seen in the Illustration (See Page 289). 
