Dr. Henry on the Philosophical Character of Dr. Priestley. 207 



for containing steam, supplied by a boiler. The inner cylin- 

 der, when in use, may be closed at each end by a door made 

 of wood or any other slow conductor of heat; and the outer 

 cylinder should be surrounded by a thick casing of any fit 

 substance, to prevent the loss of heat. From the receptacle, 

 the upper pipe may convey to the flue of the chimney any 

 undecomposed infectious effluvia. At a may be a tap for the 

 escape of air and of uncondensed steam. The outer cylinder 

 may rest, about the middle, on a wall, dividing the place 

 where it is fixed into two apartments. By this arrangement 

 all risk will be avoided of mistaking infected for disinfected 

 articles. The temperature, it is obvious, may easily be exa- 

 mined, by introducing a thex'mometer into the receptacle, 

 through a hole in one of the doors. 



The sketch is intended to convey merely a general notion 

 of the modified apparatus, the magnitude and proportions of 

 which may of course vary with the kind and quantity of the 

 articles requiring disinfection. The consumption of coal, by 

 an apparatus of the specified size, is calculated at 280 pounds 

 weight daily ; and the cost of the whole, including the boiler, 

 &c. is stated by Messrs. Galloway, Bowman, and Co. of this 

 town at 50/. 



I am, Gentlemen, your obedient servant, 



Manchester, Feb. 20, 1832. Wm. Henry. 



XXVII. Ari Estimate of the Philosophical Character of Dr. 

 Priestlaj. By William Henry, M.D. F.E.S. <$-c4-c. Bead 

 to the First Meeting of the British Association for the Promo- 

 tion of Science, at York, September 28th, 1831 *. 

 n^'H E principal source of the materials of the following pages, 

 ■*■ is the work in which the discoveries of Dr. Priestley 

 were originally announced to the public. It consists of six 

 volumes in octavo, which were published by him at intervals 

 between the years 1774 and 1786; the first three under the 

 title of " Experiments and Observations on different kinds of 

 Air;" and the last three under that of "Experiments and 

 Observations relating to various Branches of Natural Philo- 

 sophy, with a continuation of the Observations on Air." These 

 volumes were afterwards methodized by himselli and com- 

 })re.-5sed into three octavos, which were printed in 1790. As 

 a record of facts, and as a book of reference, the systematized 

 work is to be preferred. But as affording materials for the 



• From the l<'irst Iic|)ort of tlie Association : the Preface to tlie Report 

 and the Reconinicmlations of the Coniniittecs will be found at p. 225 of 

 the present Number. 



history 



