e law would entail.

It has been customary to publish, with the results of analysis, also
an estimate of the commercial value per ton of each brand of
fertilizer. This estimated commercial value is obtained by multiplying
the pounds of each element or combinations of the element in a ton by
a value per pound. To the value of the fertilizer thus obtained is
added something for cost of mixing, bagging and freight, and something
for profit. The price per pound given to each element or combinations
of the elements is based upon the commercial value of the element when
purchased in raw materials. The price for each year is usually
determined by a conference of those in control of the execution of the
law in the several states for certain groups of states. As a matter of
fact, the price varies little from year to year.

The published figures, therefore, constitute a table of comparative
commercial values as determined by the most expert knowledge. While
not constituting a statement of absolute commercial value for any
given locality, they do enable the purchaser to determine whether the
price quoted on a given brand of fertilizer is within reason. Persons
who are unacquainted with the principles controlling the use of
commercial fertilizers may, however, be led to believe that the price
of the fertilizer is an indication of its value for the production of
a given crop. As is well known to all students of the subject, there
is no necessary relation between the commercial value of a fertilizer
and the fitness of its formula for a given soil and crop. For these
and other reasons, the publication of tables of commercial value has
been strongly opposed by some manufacturers, and in certain states the
custom has been discontinued. While granting that tables of commercial
value are subject to misinterpretation, it is perhaps fair to say that
such tables have been of most benefit, and, moreover, have been of
great value to those who were most likely to misinterpret them.

It has been customary in most states to make analyses only of mixed
fertilizers. Thus such raw materials as nitrate of soda, sulphate of
ammonia, dried blood, bone meal, rock phosphate, tankage, muriate of
potash, sulphate of potash, have not been brought under the operation
of the law. If one wishes to purchase nitrate of soda, muriate of
potash and tankage with the intention of mixing them according to a
formula of his own, he may not find any protection in his