1881 .] 
• 237 
[Merrill. 
though, confessedly, this distinction depends upon whether or not 
we include among basalts only rocks which carry olivin. But that 
the alteration of dolerites gives rise to the great majority of the 
basic rocks known as diorites, is a statement which I think will 
be conceded by most students in petrography to be very extrav- 
agant. There is some danger, it must be acknowledged, of con- 
fusion arising between the older equivalent of augite-andesite 
( diabase simple) and diorite, since the former often carries horn- 
blende, and the latter augite. But there is little danger of con- 
founding the older equivalents of basalts ( i. e., melaphyr and 
olivin-diabase) with diorite, which is, mineralogically, simply the 
triclinic feldspar equivalent of syenite, and in fact such confusion 
seldom occurs. 
The author continues : “ The still more coarsely crystalline 
varieties [i. e. of basalts], when altered, gave rise to the gabbros 
and peridotites.” According to this, if the author’s meaning is 
understood correctly, the distinction between gabbro and diabase 
does not at all depend upon the presence or absence of the pyr- 
oxenic variety, diallage, but only upon coarseness of the original 
unaltered basalts from which they are derived (p. 279) ! But the 
author adds; “For the special descriptions and the tracing out 
of these changes, reference must be made to the original paper.” 
Nothing more of that original paper has ever been published, 
so far as I am informed. 1 
The following considerations may serve to show even more 
clearly than the foregoing why a speedy publication of the rest 
of the original paper is eminently desirable. 
On page 284 of the Bulletin the author says : “ As my exami- 
nation of Mr. King’s collections convinces me that his system is 
based on errors, it is well to point out briefly some of these, 
[that is, some of these errors] taking, of course, the report of 
Professor Zirkel as the basis, and following, in a measure, its 
order.” Mr. W adsworth then proceeds to notice statements of Pro- 
1 We cannot admit the deposition of the full paper in the Harvard College library 
and the fact that it may be consulted there, to be equivalent to publication in any fair 
sense. 
