T. S. Hunt on the Constitution, etc. 203 
which they were formerly made acquiring a market value, but be- 
ing exchanged for nothing so essential to their health. ‘T'here 
which have a frightful prevalence in certain districts. I mea 
the administration of potions destined sometimes to produce abor- 
tion, sometimes to cause absolute sterility, in females. Dr. Hod- 
der, in an Essay on the Poisonous Plants of Canada, read since 
the date of this paper, has alluded to the former as one of the se- 
crets of the Indians in Canada, which he has not succeeded in 
discovering, but to which he attributes, in a very great degree, 
the other. 
Arr. XXIL—On the Constitution and Equivalent Volume of 
some Mineral species; by T. 8. Hunz, of the Geological Gom- 
mission of Canada. 
In a recent paper, we have endeavored to lay down some prin- 
ciples as the basis of a sound theory of chemistry.* Having 
bination, we showed that the volumes of the uniting species are 
always merged in that of the new one, so that the atomic theory, 
as applied by Dalton, which makes combination consist in juxta- 
* This Journal for March, 1853, p. 226, and London Phil. Mag. for June, Supplement, 
p. 526. The readers of that article in this Journal will please make the following 
corrections: p. 226, 10th line bottom. for the capacity of such changes, read 
the capacity é, ete. ; in st line of the next page, 
it transcends the limits of human knowledge, read it transcends all ible knowledge. 
e etagenesis, found on 297, has been used by Owen to designate 
multiform or seri eration observed in many of the lower orders of life; this, 
however, is not strictly a metagenesis, and the term t rightly underste 
lead to grave errors. As appli ions, it appears, however, 
