16 
On the Preservation of Timber. 
copper, produce blue colours; acetate of copper yields a green 
colour ; the successive action of nutgalls and sulphate of iron gives 
a black colour ; and lastly, by treating wood, first with a weak 
solution of soda, then with a solution of bleaching-powder, after 
this with very dilute muriatic acid, and finally with pure water, 
the wood is bleached and becomes perfectly white. 
Ornamenting JFood. — Signor Muratori, in addition to colouring 
wood, has adopted the following plan for ornamenting it : — He 
first paints the surface with a preparation of Palermo white, and 
before it is dry he sprinkles over the surface pulverized coloured 
wool and Dutch metal ; he then produces a variety of patterns by 
a carved printing-block in the ordinary manner. 
Process for rendering Wood non-inflammable. 
In concluding this review of what has been proposed for the 
preservation of timber, I may remark that different patentees 
claim for their susf^estions the additional advantag-e of rendering; 
the wood non-inflammable : this object is doubtless to some 
extent accomplished, for some of the compounds of boron and 
phosphorus possess this property in a striking degree, 
Maugham has recently patented (1856) the use of phosphate of 
ammonia for this purpose. He first boils the timber, and then 
exposes it to steam pressure to expel the air, &c. : the wood is 
then dried and impregnated with a solution containing 9600 grs. 
of this salt per gallon. 
Gateshead Experiments. 
General Arrangements. — Such was the position of this 
important subject when I undertook its investigation ; and having 
occupied some time in deciding upon the most convenient form 
to be adopted in the apparatus, so as to anticipate as far as pos- 
sible the probable direction in which the experiments might lead, 
I ultimately erected a cylinder in one of the sheds at the Gates- 
head Works, sufficiently large to hold four sleepers. In the 
general arrangements the apparatus resembled that employed at 
the North Docks at Sunderland, and during the course of my 
experiments I was ably assisted by Mr. Marreco. 
After experimenting upon several sleepers with various 
chemical preparations, I found that the preservative liquids 
rarely penetrated to the centre of the timber, and I then sought 
to devise such alterations of the plans as would overcome tliis 
difficulty ; with the valuable aid of Mr. Reed this object was 
successfully accomplished. 
Alteration of Cylinder. — The nature of this modification 
will be easily understood. Each end of the cylinder was made 
