72 
It thus appears that the Key. Charles Wild bore had dis- 
covered that these properties of numbers partook of the 
nature of Porisms more than sixty years before M. Chasles 
announced the same fact in his Apergu. I am of opinion 
that the rev. gentleman was somewhat in error as to the 
contents of Euclid's Second Book ; and his opinions on some 
other points mooted in this long letter will now require 
modification. There, however, appears to be sufficient merit 
in this correspondence to warrant the publication of these 
extracts, at a time when M. Michel Chasles is astonishing 
the scientific world by his connection with the Newton 
and Pascal forgeries. 
“ On the Examination of Water for Organic Matter,” by 
Dr. R Angus Smith, F.RS. 
The Author repeated his opinion that the mere expression 
of organic matter had no such meaning as would allow che- 
mists to measure the impurity of water by its amount. He 
went more fully into the division of the organic matter into 
various portions, some acting as unwholesome agents, others 
being entirely innocent. He said he was glad to find that 
other chemists were also attending to the quality as well as 
the quantity of the organic matter, and he insisted also on 
the condition of the matter being observed. He discussed 
the methods of Professors Frankland and Wanklyn, con- 
sidered, however, that they did not supersede his own 
methods, which made a greater number of subdivisions. He 
explained the mode in which the organic matter is entirely 
removed from water, leaving frequently more of its elements 
behind, unless we include amongst them the inorganic 
bodies with which they were combined. The body which 
remains is chiefly common salt, which cannot be removed, 
and by which more than any other substance animal 
matter is to be detected in water under certain precautions. 
He also showed the importance of finding the amount of 
atmospheric oxygen in water, and its meaning ; but as the 
paper was not concluded the notice is here left incomplete. 
