244 
CORRESPONDENCE. 
It is proper to mention that the 5 -inch of 110° balsam angle was 
constructed on the plan proposed by me in the London ‘Monthly 
Microscopical Journal ’ for March, 1872, where I have made use of a 
diagram by Mr. Wenharn of a J-inch of his construction, to indicate 
modifications such as would give more than 81° or 82° in balsam. 
With proper appliances below the balsam-slide (as pointed out by 
me in the London ‘ Monthly Microscopical Journal , 7 for July, 1871), 
we can with this objective (i-inch) utilize 110 °, instead of about 81°, 
the limit of the amount of angle otherwise available. In the first 
place the large angle must have access to and through the balsamed 
object from below ; in the next place the objective must be capable of 
receiving and transmitting that dimension of pencil to the eye, which 
thing previous to my own demonstrations has not been shown to have 
been done. 
With much respect, yours truly, 
Kobert B. Tolles,” 
COBKESPONDENCE. 
Mr. Stodder and Mr. Tolles, and their Observations. 
To the Editor of the ‘ Monthly Microscopical Journal* 
October 7, 1872. 
Sir, — In the July number of this magazine a letter appeared from 
Mr. Stodder containing strictures on an article I had contributed ; of 
which I took no notice at that time, partly from the intimation it 
contained that something more would be forthcoming on the same 
subject. Perhaps, therefore, you would now allow me space for a few 
observations in reply. 
Mr. S. thinks it a breach of literary etiquette that I should have 
so unceremoniously put his error down to the account of Mr. Tolles 
instead of himself. That he was in fact prompted by Mr. Tolles, he 
admits, the prompting being, however, in this case not oral but by 
printed catalogue. But though, as it happened, correct as to the fact, I 
had no “ right,” he considers, to assume it, assuming, as it were, that he 
has not sufficient knowledge to originate a mistake for himself. But 
here Mr. Stodder has forgotten — owing no doubt to the multiplicity 
of his literary works — that he had himself published the information 
which took him so much by surprise. In the sixth volume of this 
Journal, at p. 201, he will find notice given, on his own authority, that 
he is to be considered only as the exponent of Mr. Tolles, and, with 
special reference to this particular question, that he does not presume 
not only to express, but even to possess, an opinion of his own. 
As Mr. Stodder has not time to read his own compositions, it would 
perhaps be too much to expect him to read those of others. I had 
expressed an opinion that a 1 th of Mr. Tolles might have an angle as 
high as 1G0°. Afterwards seeing Mr. Stodder’ s announcement that 
this glass has, with water, an angle of 140°, I intimated, by notes of 
