i88i.] 
Correspondence. 
175 
CHEMISM AND THE SEXES. 
To the Editor of the Journal of Science. 
Sir,— I f the duality of properties found in the elements is to be 
taken as a simple expression for sex, we ought at least to find 
such duality absolute. The behaviour of such a body as oxygen 
introduces a faCtor certainly not represented in sexual pheno- 
mena, and I think upsets the analogy drawn by Mr. Dewar in 
your January number. When Berzelius, applying his electro- 
chemical theory to the explanation duality, divided the elements 
into -f- and — groups, he himself, though imbued with the spirit 
of Lavoisier, recognised that the distinction was a relative , not 
an absolute one. 
Mr. Dewar says “ No natural production can be found con- 
taining the elements of only one class,” and that “ combination 
cannot be produced among the elements of one class only.” 
Surely he must be acquainted with carbon dioxide, and with the 
formation of, say, sodium amalgam (which is attended, by-the- 
bye, with the production of that “ old element ” flame). Appa- 
rently, however, your contributor did not trouble himself about 
elementary faCts while evolving his theory, for he describes air 
as a dual combination of oxygen, nitrogen, and hydrogen ! Mr. 
Dewar argues for the death of Materialism with the failure of his 
hypothesis, but it is an elementary chemical faCt that compounds 
may have properties totally different from those of their elements, 
- — therefore to prove that matter contains within itself the “po- 
tency of life ” one need not seek in the elements the properties 
of a definite compound, viz., Protoplasm. — I am, &c., 
F. G. H. 
SIMULATION OF ANIMALS TO PLANTS. 
To the Editor of the Journal of Science. 
Sir, — In “Tropical Nature” Mr. Wallace remarks on the simu- 
lation which naturalists on the Amazon observed in the inseCt 
tribes. Sir F. B. Head, in his “ Journey across the Pampas,” 
says he “ constantly observed the singular manner in which all 
animals, particularly birds, are protected from their enemies by 
plants and foliage which resemble them.” In his journey across 
