word 
January 28, 1897 ] 
NATURE 
295 
of comparison. If I had said only what he quotes me as saying, 
his criticism would have been justified. As it is, I say (in the 
same context) ;— 
““Verbal association and judgment are, in themselves, com- 
paratively simple processes ; but when the word associated or 
predicated is a fully formed concept, we realise that the sim- 
plicity of form is deceptive, that much mental elaboration lies 
behind.” 
“Likeness” and “difference” are concepts, and have con- 
ceptual significance. I devote a section to the formation of con- 
cepts in general (pp. 294 ff.). It is not, however, the duty of 
Psychology, but of Anthropological Psychology, to show the 
genesis of particular concepts (pp. 292, 300). I was concerned 
simply with the process of comparison as introspection reveals it 
in the adult mind, not with its logical or genetic aspects. 
: E. B. TITCHENER. 
(1) As regards the difficulty involved in counting sensation 
qualities, the point of difference between Prof. Titchener and 
myself is subtle, but philosophically interesting. 
we may both admit that the question cannot be settled 
by considerations of purely formal logic. In fact, Prof. 
Titchener’s two premisses logically lead to the conclusion 
that ‘*One sensation a zs not the same as another sensa- 
tion a, although the two are, ex Ayfothest, indistinguish- 
able.” The question between us is as to the interpretation of 
the relation ‘*not the same as”’ in this connection. My conten- 
tion is that the ove and the o/her sensation differ—not merely 
numerically or extrinsically—but qualitatively or intrinsically. 
Since the one sensation a is distinguishable from @, and the other 
sensation @ is not distinguishable from @, it seems to me that this 
difference between them cannot be referred to merely extrinsic 
conditions, but must depend on a sensationally qualitative differ- 
ence in the sensation-qualities themselves. 
(2) If I have unintentionally misrepresented Prof. Titchener’s 
views on the process of comparison, I should be glad to take 
this opportunity of making amendment by quoting a passage 
from p. 299, which seems to me sound :—‘‘ In every association 
two ideas are brought into connection. When the connection 
itself has become the object of attention, when, z.ec. we have 
formed an idea of connection, as distinct from the ideas which 
are connected, we speak of it as a ve/afton.” If this passage is 
applied to the relation of likeness or difference apprehended in 
the process of comparison, I have no ground of dispute with 
Prof. Titchener. Only in this case I fail to see how any sig- 
nificance or importance can be attached to the phrase ‘‘ verbal 
association ” employed in describing the process of comparison. 
W. E. JOHNSON. 
Durham Degrees in Science, 
AMONG the official notices of the University of Durham, I | 
find it recorded that, on Tuesday, December 15, six gentlemen 
received the degree 6f Master in Science 4y vole of Convocation. 
The degree of Master in Science has in the past been purely 
a merit degree. 
previously taken the degree of Bachelor in Science, who were of, 
at least, two years’ standing, and who succeeded in passing an 
additional examination in some branch of one of the scientific 
subjects professed at the University. The degree was, in fact, 
until to-day, an authoritative statement that the holder was not 
only a specialist in his particular subject, but also that he had 
received that sound University training in science and general 
knowledge of which the Bachelor in Science degree is a 
proof. 
This has now been changed. The degree has been granted 
merely ‘‘by vote of Convocation” for no specified cause. 
Before December 15, it was evidence of merit of a particular 
kind. Now itis not. Apart from other considerations, this is 
a great hardship upon many other graduates in science. 
Grouped together in the list of Masters in Science are those who 
have gained the honour by their scientific attainments, and those 
who have received it for non-specified reasons by vote of 
Convocation. 
Such a radical change in the nature of a degree deserves 
public notice, and this must be my apology for troubling you 
with this letter. X. 
January 1897. 
NO. 1422, VOL. 55] 
I think | 
It was conferred only upon those who had | 
NOTE ON METHOD SUGGESTED FOR 
MEASURING VAPOUR PRESSURES. 
HE distillation of vapour from one of the vertical 
tubes to the other, referred to at the end of Opera- 
tion No, 4, in my communication published in last week’s 
NATURE (p. 373), may be wholly got quit of by the 
following simplified mode of procedure. 
_ Operate first on one only of the liquids until it is got 
into equilibrium, with its upper level at any convenient 
marked point in its glass tube, and nothing but its own 
—> dwny bi 
----- - - e - 
fa a de dt 
ee oe ead 
fase 
a 
vapour between this surface and the closed stopcock 
immediately above it ; the upper-neck stopcock over the 
bottle for this liquid being also closed. 
Operate similarly on the other liquid ; and close both 
the air-pump stopcocks, so that now we have all the 
stopcocks closed. 
Open now very gradually the upper-neck stopcocks of 
the two bottles. While doing so, prevent the liquid 
from rising in either tube above the marked point by 
working the air-pump and very slightly opening the 
lower air-pump stopcock. When both the upper-neck 
1 See NATURE, Pp. 274. 
