474 REPORT—1883. 
metallic iron exercised some influence on the deoxised molecules of the colour at 
some distance from them. 
Other similar experiments were made, in which the glass plates with the disc on 
the prussian blue paper were allowed to remain for a much longer time after 
bleaching of the prussian blue had taken place, when black oxide of iron was 
adually formed round the iron discs in a remarkable manner, with alternate rings 
of the black oxide and the bleached paper upon which no black oxide was deposited. 
In one of these experiments there was produced a distinct ring of black oxide 
of iron at a distance of exactly half the diameter of the iron disc from it, the ring 
being precisely the same diameter as the disc employed. 
This circle was produced as distinctly as if it had been drawn in ink by com- 
passes, but the ring was thicker next the disc. Some months afterwards this ring 
almost faded away. 
Experiments were made with lead discs on paper coloured with chromate of 
lead, but no apparent action was produced on the colouring material. 
Glycerine jelly may thus be used for studying the influence of one metal on 
another at a distance from it, or of one piece of metal on another piece of the same 
kind, through the medium of the materials in which they are immersed, and also 
for the further study of some of the interesting phenomena mentioned herein. 
ll. On the Teaching of Chemistry in Elementary Schools. 
By Wma. Layt Carventer, B.A., B.Se., F.C.8. 
Ata recent meeting of the Physical Society the author brought forward the system 
of science demonstration in elementary schools, as practised now for some years in 
Liverpool and Birmingham. This paper appeared in full in the midmonthly July 
supplement of the ‘ Journal of Education.’ ‘he essence of the system is the employ- 
ment of a specially appointed expert, who goes from school to school with his 
apparatus, repeating the same lesson in each. The lessons are entirely oral; no 
textbooks are used; and the pupils write notes, which are revised by the demon- 
strator. Some of the results of the general system are communicated in a paper to 
Section F. 
In Birmingham a very good central laboratory has recently been erected, where 
the stock of apparatus necessary for the lessons in elementary physics is kept, and 
it has also been fitted up for instruction of a somewhat more advanced character in 
physics and chemistry. A good deal of useful work has already been done here 
by the advanced pupils, and by some of the teachers, under the supervision of the 
senior demonstrator, Mr. W. Jerome Harrison, F.G.S. He has hardly commenced 
a general system of instruction in chemistry, analogous to that in physics, since 
chemistry for the first time now forms a part of the Government code, His idea of 
the proper system, however, is— 
1, Attendance of the pupil at a course of elementary lectures, well illustrated, 
with vivd voce examinations at the commencement of each lecture upon the subject of 
the preceding one. 
2, A second course, consisting alternately of lectures and experimental work, 
the pupil in the latter performing for himself the experiments given in the former. 
These two courses to be confined to the common elements and their com- 
ounds. 
_ 3. A third course, mainly experimental, and occupied more or less with the 
analysis of simple substances, 
As at present with physics, the first of these courses would not be entered upon 
until the pupil had passed the fourth standard in the three R’s. Great importance 
is attached by Mr. Harrison to the full reproduction of lectures in notes illustrated 
by rough sketches of apparatus, &c. 
12. Anew Method for Disinfecting Sewage and Recovering Ammonia from tt. 
By J. Borp Kinnear. 
