1884.] 
On Technical Education . 
227 
in the elementary stage — have no practical knowledge of 
the sciences they pass in ; they have acquired their know- 
ledge generally, not by studying the science practically, but 
from books or lectures ; it is consequently not a knowledge 
of things, but only of names of things. It appears to me that 
in both sets of examinations, viz., those in Pure Science and 
those in Applied Science, to use the words of Prof. William- 
son, “ It is just wasting the time of students, instead of 
doing that which really might be of permanent use to them ; 
and they are sent out as conceited fellows, who are simply a 
nuisance to the factory, if they do work in it, instead of mo- 
‘destly beginning to learn the practice at the bottom.” 
Sir William Thomson stated before the Committee of 
Scientific Instruction — “ I have a general feeling that a 
Chair of Technical Chemistry has nothing to teach that is 
not better learnt in a manufactory. There is only one 
Chemistry, and that is true Chemistry ; and it is much more 
desirable, therefore, for those who are going into a chemical 
manufactory to know true Chemistry than that which would 
be of the most trivial vahie to them, — namely, to have 
attended courses of lectures upon the processes of calico- 
printing and bleaching, and the manufacture of colours, 
elaborately described, with illustrations, which the students 
are better able to see in the workshop.” 
(To be continued.) 
Note to Article on Vaccination in our last. 
* These high percentage figures have been taken as proof that the epidemic 
of 1871-2 was of exceptional severity; but they are simply a statistical delu- 
sion, or, rather, the statistical proof of the existence of a delusion, seeing that 
no more die in the total than before. To illustrate : — In 1871-2, the proportion 
of vaccinated to unvaccinated patients is given as 75 per cent, with a total 
fatality of 19 (i8 - 66) per cent. The relative fatality of unvaccinated to 
vaccinated is represented as four to one, giving percentages 44-8 and 10U5. 
Now, if the proportion of vaccinated to unvaccinated patients became go per 
cent while the total fatality, and the relative fatality of the two classes, 
remained the same, the percentage fatality of the two classes would appear as 
60 and 15 respectively, although all the aCtual conditions affecting mortality 
continued unaltered. If the proportion of vaccinated patients, under the same 
conditions, were raised to 95 per cent, the percentage figures of the two 
classes would then be 68 and 17. Contrariwise, if the vaccinated declined to 
xo per cent of cases, the corresponding fatalities would appear as only 
20 and 5. 
G. S. Gibbs, F.S.S. 
