A NEW RESPIRATION CALORIMETER 
GEORGE J. PIERCE 
It is generally known that heat is liberated, often in great quantity, 
whenever germination or fermentation takes place under such con- 
ditions that only a small proportion of the heat liberated is lost by 
radiation. For example, in the malting of barley, it is necessary to 
take precautions lest the temperature of the germinating grain rise 
too high; and California wine-makers have repeatedly told me that 
they are obliged to watch the temperature of the must very care- 
fully lest the fermentation go too fast and “the yeast burn.” Brewers 
and distillers are aware of the same fact. Botanists generally lecture 
about the liberation of heat in the spathes of aroids, but how many 
of us have seen an experiment demonstrating this phenomenon? I, 
for one, do not recall ever having seen one. I find that a considerable 
number of naturalists associate these various instances of heat libera- 
tion with rapid growth, and in some laboratory manuals of plant 
Physiology the liberation of heat is treated in connection with growth 
Phenomena. These same naturalists, and a good many others, 
think of respiration not only as involving an intake of oxygen (which 
's not always the case, as for example in anaerobic respiration), but 
© an outgo of carbon dioxid. This latter is by no means always 
the case, as the respiration of the sulphur, iron, and certain nitrogen 
bacteria shows. 
The intake of oxygen and the outgo of carbon dioxid are the easi- 
est features of the process of respiration to demonstrate in the organisms 
ordinarily studied in those biological laboratories in which any atten- 
ton whatever is paid to live plants or animals. It is easy enough for 
Us all to go on thinking of respiration as a sort of ventilating process, 
IN which a poisonous waste product of the living organism is dis- 
Placed or replaced by a useful gas. We do not necessarily realize how 
this latter gas is useful, except as it takes the place of another which 
'S Poisonous. Whether carbon dioxid is itself poisonous is, I suppose, 
°pen to dispute. At any rate, it is ordinarily of no use to the organism. 
193] [Botanical Gazette, vol. 46 
