Notices respecting Ne-w Books. G5 



this is easily prevented by softening them near the centre in the 

 spirit-lamp, and then very slightly bending them. In washing pre- 

 cipitates an inverted bottle of water is extremely useful : it supplies 

 the fluid as fast as it is wanted ; and as it requires no watching, fil- 

 tration may not only be performed during the absence of the ope- 

 rator^ but that cracking of the precipitate which occurs in many 

 cases when the filter becomes dry, is prevented. 



From the long extract which we have made, the reader will have 

 a sufficient opportunity of observing that Mr. Faraday's style is at 

 once simple and correct : there are however two passages which 

 contain (as we think) a figure of speech which we will not name, 

 but which the author will probably guess at, and in a future edition 

 alter. The first occurs in the Introduction, p. iii. " There are also 

 two parts in an experiment ; first, it has to be devised " &c. Now as 

 a thing does not exist until it is devised, we do not see how the de- 

 vising of it is a "part" of it. In p. 174. we are informed that " the 

 simplest step in the application of heat is to obtain a solution satu- 

 rated when cold." To us it appears on the contrary that the obtain- 

 ing of a cold solution is no step at all in the application of heat. — 

 We observe also that the author uses the term " lute" in two and very 

 different senses : first, in its proper sense, that of stopping the orifice 

 between a retort and receiver ; and secondly, in that of coating. 

 Now luting a retort and coating one are two different operations. 



There are i'ew philosophers, as we shall probably show, more par- . 

 ticularly, on a future occasion, whose discoveries have been more fre- 

 quently attributed to others than Dr. Priestley. This observation is 

 occasioned by a remark by Mr. Faraday, in which he ascribes to 

 Lavoisier the first use of oxygen, as a means of increasing heat. 

 The following quotations will, we think, unquestionably evince the 

 priority of Dr. Priestley. 



In his " Experiments and Observations on different kinds of Air," 

 vol. ii. edit, of ITSi, p. 100, Dr. P. remarks, " Nothing would be 

 easier than to augment the force of fire to a prodigious degree by 

 blowing it with dephlogisticated air instead of conmion air. This I 

 have tried in the presence of my friend Mr. Magellan, by fillino- a 

 bladder ivith it and puffing it through a small glass tube upon apiece 

 of lighted svood ; but it would be very easy to supply a pair of bel- 

 lows with it from a large reservoir. 



" Possibly much greater things might be effected by chemists in 

 a variety of respects, with the prodigious heat which this air may 

 be the means of affording them. I had no sooner mentioned the 

 discovery of this kind of air to my friend Mr. Mitchell, than this 

 use of it occurred to him, — He observed that platina might be melted 

 by means of it." 



And in the edition of 1790, vol. ii. p. 168, he adds to the above: 

 " These conjectures have been abundantly verified by the experi- 

 ments of .VI. Lavoisier and others." 



In concluding these remarks, and after a very careful perusal of 

 the work, we strenuously rcconnnend it, as containing the most 

 complete and excellent instructions for conducting chemical expe- 

 riments : there are few persons, however great their experience, 



Nevi Series. Vol. 2. No. 7. July 1827. K who 



