Patents^ 
45i 
designed by nature when she made them, like lire, expansible over 
all space, without lessening their density in any point ; and like 
the air in which we breathe, move, and have our physical being, 
incapable bf confinement or exclusive appropriation. Inventions 
then cannot in nature be a subject of property. Society may give 
an exclusive right to the profits arising from them as an encon* 
ragement to men to pursue ideas which may produce utility. But 
this may or may not be done according to the will and convenience 
of the society, without claim or complaint from any body. Ac» 
cordingly it is a fact, as far as I am informed, that England was, 
until we copied her, the only country on earth which ever by a 
general law gave a legal right to the exclusive use of an idea. In 
some other countries it is sometimes done in a great case and by 
a special and personal act ; but generally speaking other nations 
have thought that these monopolies produce more embarrassment 
than advantage to society ; and it may be observed that the nation^ 
which refuse monopolies of inventions are as fruitful as England 
in new and useful devices.* 
Considering the exclusive right to invention as given, not of 
natural right, but for the benefit of society, I know well the diffi- 
culty of drawing a line between the things which are worth to the 
'public the embarrassment of an exclusive patent and those which 
are not. As a member of the patent board for several years^ 
while the law authorised a board to grant or refuse patents, I saw 
with what slow progress a system of general rules could be ma- 
tured. Some however were established by that board. One of 
these was, that a machine of which we were possessed, might be 
applied by every man to any use of which it is susceptible, and 
that this right ought not to be taken from him and given to a mo- 
nopolist, because he first, perhaps, had occasion so to apply it. 
Thus a screw for crushing plaister might be employed for crush- 
ing corn cobs ; and a chain pump for raiding water might be used 
for raising -wheaWthis being merely a change of application. 
Another rule "was, that a change of material, should not give title 
to a patent ; as thC making a plough share of cast rather than 
wrought iron ; a comb of iron instead of horn or of ivory ; or the* 
connecting of buckets by a band of leather rather than of hemp 
iron. A third was, that a mere change of form, should give no 
* I doubt this. The brevet d’inrention, was a patent right in France, if I 
do not rxiislake • tiiough I do not hall it in the Co*de of the year lS04. T. C. 
