52 REPORT—1857. 
desirable that others should undertake the subject; and it was the plan adopted by 
the authors to this end, and the indications so far obtained, that they now brought 
before the Section. ‘They described the several methods adopted by M. Boussin- 
gault and M., Ville respectively, and then illustrated by drawings their own methods | 
and progress. In all cases their plants grew, in the first inslance, in soil and atmo- 
sphere destitute of all combined nitrogen, except that contained in the seed sown. To 
some, however, as their growth seemed to indicate the need, for the sake of compa- 
rison, small and known quantities of ammonia (as sulphate), were supplied. Draw- 
ings of the progress of the plants showed a very considerable increase of growth where 
this ammoniacal supply was given. In some of these cases, the plants promised to 
yield seed, and their height and general development was pretty natural. In other 
instances, where only the combined nitrogen of the seed sown, and the free nitrogen 
of the air, were available, the plants remained exceedingly small, and withered before 
coming to perfection. ‘The quantitative result could not, however, be known, until 
the growing plants, the soil, and the pots in which they grew, were analysed ; when 
the debtor and creditor account, so to speak, of the nitrogen, could be made up. Col- 
lateral researches were briefly described, the object of which was, to throw light on 
the relation of the gases evolved during the growth of plants, to constituents actually 
assimilated; and also others, to show whether free nitrogen was a product of the 
decomposition of organic matters under certain circumstances. 
| 
On the Chemical Composition of an ancient Iron Slag found at Lochgoithead, 
Argyleshire. By Joun J. J. Kyxe, Assistant in Chemistry, Surgeons’ 
Hall, Edinburgh. (Communicated by Dr. StEvENson Macapam, 
F.R.S.E.) 
This paper had reference to a discovery made by the author, during the autumn of 
1856, of a quantity of iron scoria or furnace slag, as also portions of charcoal, and 
other remains indicative of the existence, at some remote period, of an ancient iron 
work or ‘“ Bloomery” on the shores of Loch Goil in Argyleshire. The slag referred 
to, which the author has subjected to analysis, yielded him the following results :-- 
DIHCICIACION Soot at belt tema re fies ent mater eeee ee eee 
PAVIA tel; te ets d ate sh lat ah tet of wero Matis Th = tite t= ieee 
LUTTE Ve Bates: ACW Eales or ad ah Marites hcp ar thy al 
ieeTicwiA tts rete ete te eats Menthe thee oc ps a pan. cet em 
Protoxide of rane ee EN eo ee 
Di pide romenlOMnee: atta ce sets Pes eee 
Loss, with traces of manganese and phosphoric acid . . 0°76 
100-00 
Referring to the large amount of protoxide of iron entering into the composition 
of the slag, the author stated his belief that the process of manufacture adopted in 
this bloomery was in all probability that known as the direct or Catalan process, in 
which the ore is reduced by the action of the fuel, without the intervention of any 
flux, and giving rise to the formation of a silicate of iron, which from its great fusi- 
bility would readily admit of being run off at a comparatively low temperature. It 
having been long remarked that ancient scorize found on elevated positions almost in- 
variably contained a large proportion of iron, whilst those found on less exalted dis- 
tricts had but little of that metal in their composition, it had hence been inferred that 
the former indicated the more ancient seats of the iron manufacture, as, prior to the 
introduction of bellows as a means of forcing air into the burning fuel, open and ex- 
posed situations would be best adapted for furnace operations, seeing that the natural 
currents of air could have more ready access to the combustible than in sheltered 
localities ; although even by the adoption of this expedient, the operators of these early 
times would be unable to command a temperature sufficiently intense to enable them 
to employ a flux such as lime, with the view of removing the silicic acid of the ore, 
owing to the difficultly fusible nature of the calcareous silicate thus formed, From 
the preceding considerations the author drew the inference that the Loch Goil bloomery 
was one of the most ancient in the kingdom, remarking that in this view he was borne ~ 
out by the nature of the position where the remains were discovered, it being one 
which, although at no great elevation, was yet freely exposed to the sudden and high 
= 
