If the estimate were made upon three hours instead of two per
day, it is evident that the comparison would be still more in favour
of the gas lights, since the interest of capital would be the same,
and the wear and tear not much greater; so that the annual cost
might be about 650l. instead of 3000l.
The introduction of the gas lights into this manufactory has been gradual : at first some inconvenience was experienced from the smell; but this objection has been wholly removed by improved methods of purifying the gas, and it is now much approved by the work-people for the perfect steadiness of the light; and it is wholly free from the inconvenience of snufling, and from the danger occasioned by sparks that fall from candles.
In addition to the foregoing statement of comparative economy, the author conceives it may be interesting to the Society to be in- formed of the original application of this gas, as a substitute for oil and tallow, which he states to have put in practice nearly sixteen years, in consequence of experiments which he was at that time con- ducting at Redruth, in Cornwall, upon the distillation of various mineral and vegetable substances.
It was not, however, till the year 1798, that he removed from Cornwall to the manufactory of Messrs. Boulton and Watt, at the Soho foundery, and there constructed an apparatus on a large scale, for the purpose of fighting their principal building. Since that pe- riod it has been extended to the greatest part of their manufactory, to the exclusion of other artificial light; but Mr. hlurdoch has pre— ferred collecting his estimate from the apparatus of Messrs. Philips and Lee, on account of the greater extent and greater uniformity of the lights.
Although the author did not derive his information concerning the inflammability of this gas from any source but his own experiments, he has since learned that " the inflammable spirit of coals ” is men- tioned by Dr. Clayton in the forty-first volume of the Philosophical Transactions, so long since as the year 1739; and he is informed that the current of gas escaping from Lord Dundonald’s tar-ovens had been frequently set on fire previous to the date of his experi- ments: but he thinks himself entitled to claim the original idea of applying it as an economical substitute for oils and tallow for the purpose of illumination.
The author having established by the experiments which he lately communicated to the Society, that when the pylorus is closed by a ligature, fluids pass from the stomach into the circulation through the medium of the spleen. has since that time conducted a new course of experiments to determine whether there is the same passage also in the natural state of these parts.
Six asses were the subjects of as many experiments. To the three
