76 
AUGUST I4TH. 
ORDINARY MEETING.—MR. BENJAMIN LOMAX ON 
“THE RESPIRATION OF PLANTS.” 
The so-called “respiration” of plants presented one of the least 
satisfactory chapters of botanical science, and the superficial way in 
which it had been treated by even the most accomplished phytologists 
contrasted unfavourably with the thoughtful manner in which the 
corresponding branch of animal physiology had been explored by 
those who had studied it. If we asked the merest tyro in medical 
science, “ What is Respiration?” we received at once a definite and 
intelligible answer. 
“Respiration,” we should be told, consisted of three distinct 
operations. First, there was a pneumatical process. The chest 
cavity was alternately expanded and contracted by muscular action 
causing successive inspirations and expirations. This function was 
entirely dependent on vitality for its maintenance. The second 
process was hydrostatical. The blood was pumped through an infinite 
ramification of vessels, and exposed at a high temperature to the 
action of the atmosphere. Here also was an operation entirely 
dependent on vital action. The third process was chemical. The 
carbon and iron in the blood, uniting with the oxygen of the 
atmosphere, formed respectively oxide of iron and carbonic acid, 
whereof the former remained in suspension in the blood, and the 
latter was expelled. This last function was entirely independent of 
vitality, and would take place anywhere under similar circumstances 
of heat and exposure. It was especially to be remarked that the 
above changes were of the simplest character. Given muscular action, 
the rest followed as a matter of course. Above all, there was no 
decomposition, not even that simpler kind which resulted from over- 
coming a weak affinity by a stronger. The carbon was merely 
suspended in the blood; the oxygen mechanically mingled .with the 
atmosphere. Thus, two elements attached by one of the strongest 
affinities in nature were invited to conbine under the favourable 
circumstances of close contact, perfect subdivision and high tempera- 
ture induced by the chemical action itself. 
If a similar question were addressed to a student of botany, and if 
his education had been based on modern text books, he would probably 
confess utter ignorance of the matter; but if his studies had been 
among the treatises current thirty years ago, he would say that the 
green portion of plants absorbed carbonic acid, decomposing it, and 
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