392 
COMMUNICATION FROM F. R. SILVESTER. 
we have seen reason to alter our plan of applying and con¬ 
ducting the sewage over the land, which has involved expense, 
W’e have realised a profit, and are confident that the coming 
season and succeeding years will very well remunerate us. 
I know that my father will have much pleasure at any time 
in answering any inquiries you may wish to make, and to 
afford any information on the subject in his power.—I am, 
sir, yours very respectfully, 
“ Alexander M‘Dot;gall, jun.” 
Allied to the above is the proposed inquiry, moved for in 
the House of Lords, by the Earl of Derby, and carried, into 
the injuries caused to the land by noxious vapours evolved 
during certain manufacturing processes, which poison the 
air and the rivers, destroying both animal and vegetable life. 
This is seen in the arsenical vapours emitted from tin 
works, and during the smelting of copper; of muriatic acid 
gas, in the manufacture of soda from common salt and sul¬ 
phuric acid, and other gaseous compounds from lead and 
other works. The object of his lordship is to protect the 
community from the injurious effects of these eliminations. 
Thus it is that science comes to the aid of commerce; for 
rightly has it been said that, “Agriculture has been called 
forth to take its position in commerce, and commerce is learn¬ 
ing its identity w r ith the interests rooted in the soil;” w 7 hilst 
man’s inventive powers are exercised to prevent the evils that 
w r ould otherwise arise in the production of the necessaries of 
life, and to utilise that which might prove poisonous. It is 
true that many of those necessaries, so designated, are arti¬ 
ficial, nevertheless they are the result of the progress of 
civilisation, which it is impossible to check, nor is it desir¬ 
able to do so. At any rate, it cannot be gainsaid that health 
is of paramount importance, whether in an animal or a vege¬ 
table ; and each, the highest as well as the lowest, is alike 
dependent on the same physical causes for existence, w r hile 
each also subsists by and for the other, constituting the great 
circle of organisation. 
COMMUNICATION 
From F. R. Silvester, M.R.C.V.S. 
St. Albans; June 12, 1862. 
My Dear Sirs, —There is an error in this month’s 
Veterinarian , in the report of what I said at our last annual 
