298 Advantages and Disadvantages of 
to see the evils and abuses with which they are sometimes 
attended, and to which they are always more or less liable, as 
far as possible removed. 
It is to be regretted, as being, however, an almost unavoid- 
able evil, that works on natur: ar history are, for the most part, 
necessarily expensive, especially if they contain plates ; still 
more, if the plates are coloured, as, in many cases, they must 
be, fully to answer the purpose intended; and, most of all, if 
these are really well executed, and the work splendidly got 
up. The cost, for example, of such a work as Sowerby’s 
English Botany (not to take one of larger calibre), extending 
as it did to six and thirty g Ppedeeds volumes, though pub- 
lished at a moderate price, would amount (I speak at a rough 
guess) to, perhaps, near 50/1. or more. Now, this may be 
thought a serious sum to pay for a favourite hobby, for the 
mere : gratification of one’s taste; and many of those who took 
the work in would have been deterr ed, I suspect, from pur- 
chasing it, had the money been to be paid down for it in a 
lump. But, as it came out in monthly numbers, and occu- 
pied a course of years in its completion, we some of us now 
find our libraries enriched with a costly and truly valuable 
book, which, had it been published all at once, we might 
hardly have thought ourselves justified in purchasing. It will 
be said, perhaps, in reply, that this way of representing things 
is mere self-delusion, invented for the sole purpose of quieting 
the consciences of those who choose to indulge in such elegant 
and expensive luxuries; for that the same identical sum of 
money, to a penny, is paid for the article, whether it be taken 
in serzatim or bought complete. No doubt, the same sum 7s 
paid; but, being paid gradually, and by small instalments, dis- 
tributed, as it were, through a course of many years, the tax 
falls lightly, and is scarcely felt. This, then, is one of the 
advantages of publishing works in the form of periodical 
numbers: it brings them within the reach of men of moderate 
means ; and, therefore, extends their circulation, and, conse- 
quently, their utility. 
Another advantage of this method is, that it gives oppor- 
tunity, not only for “correcting ¢ any mistakes which the author 
may have inadvertently fallen i into at the commencement of his 
labours, but also for including i in the work all the recent dis- 
coveries, which are continually being made during the pro- 
gress of publication, and thus renders the Flora or Fauna, 
&c., far more complete than it could have been, had the whole 
issued simultaneously from the press. Take, again, as an 
example in point, the case of English Botany, the first volume 
of which bears, in the titlepage, the date of 1790, and the 
