46 Notices respecting New Booh. 



been, our author seems to agree, for Dr. Priestley alone is selected 

 for reprobation on this subject, with which, we may remark, the 

 author had no business to intermeddle. It is, he says, " upon his 

 philosophical writings the reputation of Dr. Priestley must rest ; 

 his theological opinions are most deservedly condemned." Does 

 the author thus go out of his way to anathematize Dr. Priestley for 

 heterodoxy, lest his own reputation for orthodoxy* should suffer by 

 having lauded the Doctor's discoveries in science ? We cannot 

 imagine the existence of any motive more favourable or more weak. 

 We may remark that no mention is made of the labours of the late 

 and lamented Dr. Henry ; and Dr. Wollaston is stated to have died 

 in the 53rd instead of the 63rd year of his age. 



We now proceed to consider the chapter on oxygen, and in page 

 140 the following statements occur : " Every human being on the 

 face of the earth consumes nearly twenty- five cubic feet of oxygen 

 every twenty-four hours (45,000 cubic inches daily, according to 

 Lavoisier, Seguin and Davy), and one hundred weight of charcoal 

 requires for its combustion thirty-two cubic feet, yet notwith- 

 standing this immense hourly consumption, the quantity of this 

 essential principle is not diminished in the atmosphere, but bears 

 the same proportion to the nitrogen the other ingredient, now, as it 

 did centuries ago." 



We shall not object to the statement that 25 cubic feet of oxygen 

 are in twenty-four hours consumed by every adult, but we may ob- 

 serve that this quantity is equivalent to only 43,200 instead of 45,000 

 cubic inches. The experiments of Messrs. Allen and Pepys give only 

 39,354 cubic inches, while according to Liebig's statement, that 14 

 ounces of carbon are daily discharged from an individual, the oxygen 

 consumed in twenty-four hours will amount to 47,480 cubic inches ; 

 we will therefore take Mr. Noad's statement of 25 cubic feet, which 

 would combine with nearly 12- 75 ounces of carbon ; if then 12" 75 

 ounces of carbon require 25 cubic feet, 112 pounds of charcoal, or 

 1792 ounces, will combine with three thousand five hundred and 

 thirteen cubic feet of oxygen, instead of 32, as stated by our author. 

 It is not easy to imagine how so enormous a blunder could have 

 been perpetrated in the first instance, but it is truly marvellous that 

 it did not occur to the author in correcting his proof, that according 

 to this statement " every human being on the face of the earth " 

 must by respiration give out ff of 112 pounds of charcoal, or 87£ 

 pounds in every twenty-four hours. 



The assertion of Mr. Noad, though probably true, that the quan- 

 tity of oxygen in the atmosphere is the same that it was centuries 

 ago, is utterly incapable of proof.; for oxygen itself not having been 

 discovered 70 years, we presume Mr. Noad will admit that no ex- 

 periments could be made on its quantity before it was known. 



There is much requiring correction in the author's statement re- 

 specting the means to be employed for procuring oxygen gas : for ex- 

 ample, we are informed that a pound of peroxide of manganese of good 



* As he sets up for an authority in theology, it is to be hoped he is freer 

 from errors on the subject than we have found him to be in chemistry. 



