LECTURES ON CHEMISTRY. 
753 
perhaps, than from any other mode of instruction alone considered, 
— yet all the lecturer can do is to offer to the student an outline , 
which is to be filled up by means of subsequent study. Lecturers , 
then , are but adjuvants to the acquirement of knowledge ; and it 
is alone by serious thought and reflection that solid information 
can be effectually engrafted on the mind. 
How many commit a sad error here ! They think that, because 
they have sedulously attended the lectures, they have done all 
that is or can be required of them to do. Fatal mistake ! and 
not often found out until it is too late. 
“ Man/’ says Paley, “ is a bundle of habits.” How necessary, 
then, is it that we should be rightly directed at the onset of our 
career in life, in order that the good may preponderate over the 
bad ! for the saying is a true one, “ as the twig is bent, so grows 
the tree/ 7 
Next to an attendance upon lectures as a means of acquiring 
knowledge certainly comes reading. And here let me offer you 
a word of advice. Never come before the lecturer with your 
head stored with recently acquired information on the subject 
upon which he is about to treat. You will do well to remember that 
“ a vessel which is full can hold no more.” Beyond this, the 
act will engender carelessness and indifference during the delivery 
of the lecture. The matter may appear familiar to you from your 
having just read about it, and the observations which may fall 
from the lips of the teacher will then cease to interest or make 
any impression, and, consequently, as you have only acquired a 
superficial knowledge, it will pass away as the morning cloud or 
the evening dew. 
I may, perhaps, be allowed to add another reason. Carelessness 
in one will induce carelessness in another. This will manifest 
itself in the smile, or the thrust with the shoulder or the elbow, 
the pointed finger, or the titter at some trifling event — perchance 
some unfortunate blunder which the lecturer himself might have 
made, or that over which he had no controul, — the failure of an 
experiment. 
Think then. Gentlemen, what are his feelings ! — his mind being 
absorbed as it were in his subject — his whole thoughts were con- 
centrated there — by this one act of yours his fears are awakened, 
and he becomes distracted and perplexed. Others as well as 
himself are annoyed ; and that by an act, perhaps, on your part 
unintentionally committed. 
My advice, therefore, is to read the subject over thoughtfully 
after you have heard the lecture ; of this being assured, that the 
one without the other is of little worth. 
Next to this I would place mutual instruction. I am pleased 
VOL. XIV. 5 G 
