EDITOR'S TABLE. 



495 



the ambient air by the chemical law of 

 gaseous diffusion. Does any one suppose 

 that, amid sources of contamination, stag- 

 nant water would be purer than running? 

 Had Dr. Niemeyer used his nose, or attended 

 to its monitions in his midnight ramblings 

 among the .sick, he could never have penned 

 such an erroneous sentence. Only solici- 

 tation that your journal shall occupy the 

 highest grounds in all its selections animates 

 this criticism from my pen. 



J. R. Black. 

 Newark, Onio, December 22, 1877. 



"THE LAW OF CONTINUITY." 



To the Editor of the Popular Science Monthly. 



In the interest of scientific accuracy, I 

 would call attention to one or two state- 

 ments in the article on " The Law of Con- 

 tinuity," in your November number, which 

 are either greatly strained or positively erro- 

 neous. 



The author of the article in question 

 says, speaking of sulphuric acid and water, 

 " In all possible percentages do these liquids 

 chemically combine, and this is at variance 

 with the generally obeyed law of definite 

 proportions " (page 32 the italics are 

 mine). This is a very loose use of language, 

 as may be easily demonstrated by a com- 

 parison of this passage with the statement 

 of the fact by any scientific authority. For 

 example, Fownes (" Manual of Chemistry," 



eleventh edition, p. 203) says: "The most 

 concentrated sulphuric acid, or oil of vitriol, 

 as it is often called, is a definite combina- 

 tion of 40 parts sulphuric oxide and 9 parts 

 water. ... Oil of vitriol is not the only hy- 

 drate of sulphuric oxide ; three others are 

 known to exist. When the fuming oil of 

 vitriol of Nordhausen is exposed to a low 

 temperature, a white crystalline substance 

 separates, which is a hydrate containing 

 half as much water as the common liquid 

 acid. Further, a mixture of 98 parts of 

 strong liquid acid and 18 parts of water, 

 2HoOS0 3 , or H 2 S0 4 H 2 0, congeals and re- 

 mains solid even at 7.2 C. ( 45 Fahr.)," 

 etc. There is, then, in the case of sulphuric 

 acid and water, at least, a clear enough 

 distinction between mechanical mixture and 

 chemical combination, although Mr. lies 

 quite loses sight of it. 



Then, again, he says (p. 30), " Science is 

 unable to give us any metal but gold in a 

 translucent state." The inability does not 

 lie with " science." It has long been known 

 that silver may, by chemical means, be ob- 

 tained in a translucent film. And likewise 

 platinum, aluminum, bismuth, copper, lead, 

 iron, nickel, cobalt, palladium, zinc, cadmi- 

 um, magnesium, and other metals, have been 

 procured in a layer so thin as to be trans- 

 parent (Wright, American Journal of Sci- 

 ence and Arts, No. 73, January, 1877). 1 



Latncelot W. Andrews. 

 Springfield, Mass., November 8, 1877. 



EDITOR'S TABLE. 



COOK AND HIS "-BIOLOGY:" 



THE Rev. Joseph Cook seems to 

 have attained the position of an 

 accepted champion of orthodoxy in its 

 conflict with the science of the time, 

 and as such must have a degree of at- 

 tention to which he is not otherwise en- 

 titled. In the delivery of the lectures 

 which compose his volume on biology, 

 he was listened to, we are told, by 

 large audiences of cultivated and schol- 

 arly men, who applauded him enthu- 

 siastically ; while the book has been 

 highly praised by eminent theologians 

 and numerous newspapers, and has had 

 a brisk and extensive sale. Yet we ob- 

 serve that the tide of encomium is per- 

 ceptibly falling, and shrewd orthodox 

 people are beginning to see that they 



cannot too quickly relieve themselves of 

 responsibility in regard to his work. In 

 an able review, in the January New- 

 Englander, the scientific charlatanry of 

 Mr. Cook's book is thoroughly exposed; 

 its taste and rhetoric are pronounced 

 "execrable," and the writer closes by 

 saying that "this production is not one 

 for orthodoxy to be proud of, and that 

 it is best to declare this opinion plainly 

 and promptly." 



Nevertheless there is a startling sig- 

 nificance in the fact that such a work 

 could have received from an intelligent 

 Christian community the measure of 

 commendation that has been accorded 



1 It is but fair to s=ay that the article in ques- 

 tion was written and in the hands of the editor 

 six months before Prof. Wright's researches 

 were published. Ed. 



