29 
of Edinburgh , Session 1878 - 79 . 
summer of 1839, but was detained for some time at Amsterdam by- 
rheumatic fever, and obliged to return home from great prostration. 
Throughout many years of his life he suffered from frequent attacks 
of the same kind, often checking him in the midst of work. How- 
ever, he was not long after this ready with a paper “On an 
Anomalous Condition of Iron.” Experiments were detailed, showing 
iron to be positive when compared with copper, and yet far more 
highly negative than copper when compared in their electric relation 
with zinc. The result of this newly discovered fact was, that he 
recommended to the Admiralty a new method of sheathing ships, 
and made known the use to which it might be applied in the manu- 
facture of boilers. 
In 1851 he contrived a battery for obtaining products that might 
be utilised in the arts, and thus cheapen the use of electricity, but 
soon afterwards those products became so plentiful as to be of little 
commercial value. 
For the same purpose, he recovered his products and used them 
over and over again without much waste. It is interesting, at the 
present moment, to read the description of an electric lamp, for 
which he then took out a patent, but which was not carried into 
general use for want of sufficient funds. The distance between 
the graphite or charcoal electrodes was regulated by a kind 
of clockwork, and two sets of electrodes used to produce equality 
of light, or else “the electrodes were placed in a vacuum, or 
space not containing any oxygen or other matter which could 
cause their destruction when brought into an incandescent state 
by the action of the current of electricity.” The specification, 
with full drawings, dated 1852, No. 14, 198, may afford some hints 
for those at work in a similar direction now. It may not have been 
known to those who have lately proposed the same thing, but the 
coincidence is singular. While visiting the manufacturing districts 
of Glasgow and Leeds, he used his chemical knowledge to improve 
the making of paints and dyeing of woollen cloths, and also helped 
in reducing the friction of spindles. It should here be mentioned 
that, in the course of his life he took out several patents, but a mind 
so sensitive as his was not fitted for the wear and anxiety of com- 
mercial speculation, and the fertility of his thoughts would not 
allow him (like the man of one idea) to rest long on anything he 
