November 29, 1894] 



NA TURE 



107 



more orderly arrangement, and one more convenient for refer- 

 ence, is also the one that best enables the student to study the 

 subject in the way advocated by my reviewer ; and in order lo 

 impress upon the student that the study of descriptive facts 

 should accompany the study of the reasoning on these facts, he 

 is directed to "slowly and carefully " read part \. while he is 

 studying the descriptive chapters. I venture to think also, that 

 this method tends far less to " perpetuate the vicious and unreal 

 distinction between chemistry and chemical philosophy ' than 

 that of obliging the student to gain his information ol facts from 

 one book, and his knowledge of theory from another. 



Commenting upon the fact that part ii. is devoted to the study 

 of four typical elements, Mr. Muir says : 



" But hydrogen, oxygen, nitrogen, and carbon are not 

 treated as typical elements ; they are not compared and con- 

 trasted with other elements." 



This criticism is not true. Chapter ii. of part iii. is prefaced 

 with a short general account of the elements oxygen, sulphur, 

 selenium, tellurium, in which the typical element oxygen is 

 compared and contrasted with its conjrires. Chapter iii. is 

 prefaced with a similar brief sketch of the elements nitrogen, 

 phosphorus, arsenic, antimony, bismuth, wherein the typical 

 element nitrogen is compared and contrasted with the others of 

 the group ; and similarly at the beginning of chapter ix. the 

 typical element carbon is compared and contrasted with silicon, 

 i;ermanium, tin and lead. 



My reviewer is good enough to say : " The descriptions in this 

 ook of the members of each group of elements seem co me to 

 e exceedingly well done ; many portions of the chapters treat- 

 i\l; of principles and theories . . . are admirable." And again, 



few lines further on : " The purely descriptive portions of the 



ijrk are often extremely good, as far as they go. The facts, 

 r rather half-facts, are stated in a clear and orderly way." 



I am a little curious to know what half-facts are ; and 

 whether if such things can be, it would be possible to state them 

 " in a clear and orderly way." If my reviewer merely means 

 that there are so many more facts known than I have stated, 

 hat roughly speaking it may be said that I have only described 

 ne half of the known facts, I can only reply that I have 

 'endeavoured to select *' from the overwhelming burden of so- 

 called facts " such as seemed to me to be most important for the 

 student, and which could be conveniently included within the 

 limits of a small text-book. 



Mr. Muir finds fault with my book because he does not dis- 

 cover in it "some fair and fitly fashioned building," which he 

 says "ought to rise on this broad superstructure " I regret 

 that this objection has not been stated in rather more explicit 

 terms ; I have ttied to understand it, but cannot — perhaps it is 

 poetical. In ordinary language one does not speak of a build- 

 ing as rising upon a superstructure. In no text-book of chemistry 

 with which 1 am acquainted, is any trace of such a phantom 

 edifice to be found, and it is sincerely lo be hoped, that when 

 the Joshua appears, who by raising such a "fitly fashioned 

 building" shall "rescue chemistry from the overwhelming 

 burden of so-called facts beneath which the science is in danger 

 of being buried," he will choose some more suitable vehicle for 

 making his views known to the scientific world than that of an 

 elementary text-book on inorganic chemistry. 



G. S. Newxh. 



I STILL hold that Mr. Newth's method is radically wrong. 

 I admit it is not easy to make the descriptive statements of 

 chemical facts accompany the reasoning on these facts ; but 

 although not easy it can be done. 



As regards Mr. Newth's treatment of the four typical 

 elements, hydrogen, oxygen, nitrogen, and carbon, I can only 

 repeat that the comparisons and contrasts made between these 

 elements and those of which they are representative are, in my 

 opinion, worth very little. 



I cannot enter into a discussion of the meaning of the term 

 "half-fact" ; but I can assure Mr. Newththatin saying he had 

 staled "half-facts in a clear and orderly way," I did not mean 

 to say he had stated about half of the known facts and omitted 

 the rest. It is characteristic of hall-facts that they are very 

 amenable to clear aud orderly arrangement. 



When I spoke of " some fair and fitly fashioned building " 

 rising "on this broad superstructure," of course I should have 

 written "broad substructure." I am much obliged to Mr. 

 Newth for pointing out this stupid slip. 



NO 1309, VOt. S'] 



I thought Joshua was more concerned with demolishing towns 

 than with raising buildings ; but my Hebrew history is a 

 little rusty. M. M. Pattiso.n Muir. 



Cambridge, Nov. 21. 



Singing Water-Pipes. 



At Oxford, Prof. Osborne Reynolds showed an interesting 

 case of sound in water. There is another familiar effect, of 

 which he has probably given the reason, but it does not seem 

 to be commonly known. 



A little while back there was a clear steady note carried 

 through my house by the water-pipes, a note of the middle 

 octave of the quality of an organ diapason pipe. When the 

 source was found, it was easy to change the note through the 

 octave. The music arose as often as the scullery tap was 

 turned on, and lasted so long as the water was running. The 

 tap was worn, and the flow of water kept up a rapid tapping of 

 the loose part, just as in Trevelyan's Rocker. 



The singing is sometimes heard after a tap is turned off. 

 This happens because the ball-tap of a cistern has thus been left 

 running. W. B. Croft. 



W'inchester College, November 26. 



An Aurora on November 23. 



Steppi.n'g out of doors to-night, November 23, at 7.30, 1 was 

 surprised to see the whole northern sky filled with luminous 

 mist, so clear that our shadows were dimly observed on the 

 shining surface of the wet highway. There were few tremulous 

 motions, but the light clouds advanced southwards in great 

 patches. For a while the planet Jupiter shone to the east of the 

 luminous haze. Then the mist passed over Jupiter, who shone, 

 however, with nearly its wonted splendour until a great de- 

 tached belt hung between Jupiter and Pleiades, over to the 

 south-west horizon. 



The Milky Way became obscured as the haze passed right over 

 our heads. By eight o'clock the detached luminous belt, which 

 was not uniform, but in patches, had reached the planet Mars. 

 Neither was the light in the north uniform, but here and there 

 were clear spaces. By 8. 10 the aurora was much dimmer. By 

 8.30 there was no luminosity except in the north, between the 

 Great Bear and the horizon. J. Shaw. 



Tynron, Dumfriesshire. 



A Snake "Playing 'Possum." 



A ruFFi.NG adder, Heterodon platyrhintis, caught by the 

 writer in May 1894, exhibited a most curious instance of feigned 

 death which may be worthy of record. 



The snake when discovered at first tried to escape, but on 

 being captured it turned on itself with mouth wide open, head 

 thrown back sharply, and tongue limp and protruding. The 

 mouth remained open thus to its fullest extent, while the head 

 and upper part of the body threshed violently from side to side 

 for a few times, and then his snakeship rolled over on his back, 

 and after a few convulsive movements became apparently lifeless. 

 The body was then quite limp, and remained in whatever posi- 

 tion it was placed, providing the snake was on his back, but 

 when turned over in the proper position, he immediately rolled 

 back by an almost imperceptible muscular contraction. When 

 struck lightly, pinched or held up by the tail, there was very 

 slight resistance. He continued in this state for about half an 

 hour, when no attention having been paid to him, he resumed 

 his normal position. A little leasing caused a repetition of this 

 performance a number of times afterwards, and it did not vary 

 in any essential particular. It would be interesting to know 

 whether this is a ruse common 10 individuals of this species, and 

 if so whether it is confined to them alone. 



L. C. Jones. 



The Soaking of Seeds. 



In reply to Mr. Alfred W. Bennett's inquiry as to the 

 soaking of seeds in milk before sowing, it may interest him to 

 learn that in book iii. section v. of his "Deipnosophists," Theo- 

 phrastus is quoted by .-Mhen.-eus as saying that "cucumbers 

 contain a more agreeable and wholesome juice if the seed be 

 steeped in milk or mead before it is sown," and that "plants 

 come up quicker if they are steeped in water or milk before 

 they are put in the ground." P. C. Glubb. 



Pendean, Liskeard, November 13. 



