NATURE 



\lSlov.Z, 1877 



" British Columbia 

 ' ' Drcnuned by a Devil Fish 



" Victoria, September 27. — An Indian woman while bathing 

 was pulled beneath the surface of the water by an octopus or 

 devil fish and drowned. The body was discovered the following 

 day in the bottom of the bay in the embrace of the monster. 

 Indians dived down and with their knives severed the tentacles 

 of the octopus and rescued the body. This is the first recorded 

 instance of death from such a cause in this locality, bat there 

 have been several narrow escapes." 



Exeter College, Oxford H. N. Moseley 



The Earthworm in Relation to the Fertility of the 

 Soil 



In Nature, vol. xvii., p. 18, there is an account under the 

 above heading of M. Hensen's investigations of this subject, to 

 which I wish to add a note. He says the assertion that the 

 earth-worms gnaw roots is not proved by any fact ; roots gnawed 

 by worms were never met with by him, and the contents of the 

 intestines of the worms never included fresh pieces of plants. 

 The experience of gardeners that the earth-worm injures pot 

 plants may be based on the uncovering or mechanical tearing of 

 the roots. 



I should have thought that the universal experience of 

 gardeners is that earth-worms never eat vegetable matter until it 

 has decayed, and that their instinct leads them to draw the 

 points of leaves as far as they can into their tubes for the purpose 

 of setting up the decaying process, and likewise to sever the 

 roots of pot plants with the same object. I can hardly under- 

 stand how earth-worms have any mechanical means of severing 

 the roots of plants except by gnawing. 



But there is an omission in M, Hensen's account of the ferti- 

 lisation of the subsoil by earth-worms which surprises me. He 

 mentions but two ways in which this is effected, viz., by the 

 opening of passages for the roots into deeper parts, and by the 

 lining of these passages with humus. 



I thought it was a well-known fact that worms, by means of 

 their "casts," effect a complete renversement of the soil of 

 meadow land down to a certain depth in the course of a few 

 years. But whether wdl-known or not I met with a demon- 

 stration of this important fact in 1857. When putting down a 

 considerable extent of iron fencing iu the alluvial meadows near 

 my house (consequent upon an exchange of land) I had occasion 

 to cut a ditch two or three feet deep, and when the workmen 

 had finished the ditch — a quarter of a mile long in all — I was 

 astonished to see in one portion, of about sixty yards in length, a 

 distinct and very even narrow line of coal-ashes mixed with small 

 coal in the clean cut surface of the fine loam of the ditch face, per- 

 fectly parallel with the top sward. It immediately occurred to me 

 that this was the work of the earth-worms, and upon inquiry I 

 found that the farmer, who had occupied this land for many 

 years, remembered having once, and only once, carted out some 

 coal-ashes and spread it at this spot not many years before. I 

 forget the exact number of years, but I believe it was about 

 eighteeen. I have a distinct recollection, however, that the 

 depth of the line of coal-ashes below the surface was at least 

 seven inches, and that this seemed to confirm the general belief 

 that the depth to which the earth-worm usually burrows is about 

 that amount. I may add that the colour of the loam above the 

 line of coal-ashes was decidedly darker than of that below. 



Henry Cooper Key 



Stretton Rectory, Hereford, November 2 



In Nature, vol. xvii. p. i8, some details are given of 

 observations made by M, Hensen on the relation of the earth- 

 worm to the fertility of the ground. He has observed, as 

 everyone must have observed, that the earthworm during night 

 draws into its tube or hole the loose leaves and fibres which may 

 be lying about. But this operation of the earthworm has a 

 significance in relation to the vegetable world of even a pro- 

 founder kind than that of the fertilisation of the soil. Some 

 months ago, in searching for young ash plants with three 

 cotyledons, I found that in a great many cases the samara or 

 seed of the ash had been drawn into a worm's hole, and had 

 there found moisture and other essential conditions of growth ; 

 while the same seeds lying dry upon the surface had not germi- 

 nated. There can thus be no doubt that many seeds of all 

 kinds are drawn under the surface of the ground, or covered by 



the earth thrown up by worms. They are thus preserved from 

 birds and various enemies, and are placed in the proper position 

 for germination. The dead plant is perpetuated from its fallen 

 panicle by the earthworm. An ash tree, or a whole forest of 

 ash trees, may have been planted by earthworms. 

 North Kinmundy, November $ A. Stephen Wilson 



M. AUuard's Condensing Hygrometer 

 The notice of the above instrument in last week's Nature 

 (p. 14) is an excellent illustration of the necessity for increased 

 communication between the scientific men of all countries. The 

 labour which is at present wasted by repeating what has been 

 done before is enormous, and until international intercommuni- 

 cation is improved it must be so. 



I quite agree with you in your appreciation of M. AUuard's 

 hygrometer, but I think it is desirable to state that it is not the 

 first in which "the part on which the deposit of dew is to be 

 observed is a plane well-polished face a, of silver or gilt brass." 

 The annexed engravings represent the form of plane- faced 

 hygrometer invented by Mr. G. Dines, F. M.S., described by 

 him in the Meteorological Magazine for October, 187 1, and 

 exhibited at the Brighton Meeting of the British Association, 

 1872. 



The action is extremely simple ; no ether is required nor any 

 aspirator. Water colder than the dew point is the only requisite 

 — it is poured into the reservoir A, passes through the regulating- 

 tap B into the chamber D ; it is, by the black diaphragm, thrown 

 past the bulb of the thermometer c, and then allowed to escape. 

 The cooled plane surface E of silver or black glas=, is excessively 

 thin, and the space between it and the thermometer-bulb is 

 wholly occupied by the effluent water, so that the great essent'al 



Section 



of all hygrometers, a true indication of the temperature of the 

 cooled surface, seems to be reached. The plate e can be kept 

 within o°'2 or o°'3 for a length of time by adjusting the screw B, 

 and as the condensation usually takes an elliptical form over the 

 thermometer-bulb, and in the middle of e, the advantage of an 

 adjacent bright surface is usually attained. I am, hov/ever, not 

 sure that M. AUuard's surrounding plate might not be a con- 

 venience, although for the reason above given I have not found 

 it necessary. G. J. Symons 



62, Camden Square, N.W., November 2 



Optical Spectroscopy of the Red End of the Solar 

 Spectrum 



Nature, dated August 2 (vol. xvi. p. 264), containing Pro*". 

 Piazzi Smyth's communication on " Optical Spectroscopy of the 

 Red End of the Solar Spectrum," reached me on the 2ist ult., 

 when I had no leisure to avail myself of the outgoing mail and 

 reply immediately to the subject of his last paragraph. Inquiry 

 is there made of "anyone" (besides the Royal Society), in 

 association more or less with my name, whether more recent 

 particulars have been published, of the spectrum in question, 

 than "those {i.e. my) Indian observations," "printed in the 

 Philosophical Transactions so long ago as 1874" {i.e. 1875). 



2. The Astronomer- Royal for Scotland is presumably in a 

 better position to reply for "any one," than myself, located in 

 latitude N. 30°, longitude E. 78° ; and so far as the inquiry 

 relates to the Royal Society, his penultimate paragraph in itself 

 furnishes the information sought, because the Society's publica- 



