290 



NATURE 



\7tcly 24, 1879 



noticed af pr'.rently, till I had gained sufficiently on M'Guire to 

 make him hear. I then coo-eed once ; he turned and came back 

 to meet me ; but at the sound of my coo-ee the fish started off 

 seawards oiit of sight (under water), and doubled again in-shore, 

 but so rapidly as to leave both outward and inward " ridge " on 

 the water distinctly visible at once, like a wide V with quite a 

 sharp comer. It gave me the idea of two fishes, the one darting 

 outwards, the other crossing its track inward at the same 

 moment. 



" Not knowing where it might show up next, but satisfied that 

 it had come in-shore again, I tried by pointing seaward to direct 

 M'Guire's attention that way. 



" Just as I met him the fish again came to the surface, showing 

 gradually more and more of his length, till, when he was almost 

 at rest, and all apparently was in view, I estimated the length to 

 be 60 feet, straight and taper, like a long spar, with the butt-end, 

 his head and shoulders, showing well above the surface. 



" I can only describe the head as like the end of a log, bluff, 

 about two feet diameter ; on the back we noticed, showing very 

 distinctly above water, several square-topped fins." 



I here make an exact tracing from Mr. Brown's letter of his 

 sketch : — 



Vul 



\-y — L 



B^ad, 



" It was now getting rather too dark to see details distinctly. 

 The fish proceeded towards Lockville, and I turned homeward. 

 M'Guire said he would go en to Lockville jetty and look out for 

 him there. 



" Whether he saw him again I know not, but M'MuUan, the 

 fisherman, told me next morning that he had seen it about fifty 

 yards from that jetty, and it looked to him about twenty feet 

 long. So it did to me while in motion ; only when at rest for a 

 moment did its whole length show up sufficiently. What its 

 propelling power was I cannot say from observation ; I saw no 

 lateral fins and no fish-tail. 



"When it started away at the sound of my voice, it was with 

 the rapid movement of a pike or sword-fish, and yet .the thick, 

 iluff head had but little resemblance to a snake's. 



' ' There was an unusual abundance of fish close in-shore the 

 same afternoon, yet when I saw the stranger there were certainly 

 no fish of which it could be in pursuit." 



Since the year 1848, when the captain and officers of a British 

 man-of-war gave evidence that they passed within 100 yards of a 

 snake which they estimated to be 60 feet in length above water 

 with probably 40 feet beneath, I do not know of any more clear 

 account than the above. Many independent accounts of the 

 existence of marine monsters have been placed on record, and it 

 seems mere folly to treat these repeated reports with ridicule. 



I trust that your readers will no longer doubt that " the age of 

 incredulity " is past. H. C. Barnett, 



Fremantle, W. Australia, May 19 Colonial Surgeon 



Mechanical Difficulty in Growth of Plants and Animals 



In reading reports and discussions on natural science, to 

 which I am, from great pressure of other occupation and 

 studies, only able to give a cursory attention, I cannot find 

 any allusion to the mechanical means by which the growth of 

 organised creatures is produced, especially when that growth 

 takes place in opposition to the direction of gravitation. The 

 explanation at which I have arrived of this phenomenon may 

 probably be known to physiologists, and may have been ac- 

 knowledged or disproved ; any way I think the subject might be 

 fairly discussed in a popular journal such as yours. 



The growth of the roots of a plant and _of drooping branches 

 not being in opposition to the attraction of the earth, presents 

 only the difficulties which arise from vital action, but the in 

 crease of a plant in height requires also explanation as to how 

 the work is done of lifting vegetable matter higher and higher ; 

 capillary attraction can bring fluid to the summit of a tube such 

 as the stem of a plant, but the fluid cannot overflow at the top, 

 since in that case the matter of the tube would lift the fluid above 

 itself ; but \^ hen a tube is full of fluid, additional heat expanding 

 this fluid would cause it to overflow at the top of the tube. As the 

 sap contains solids in solution, from this the fluid could deposit 

 an additional length of tubing, in which again an additional 

 length of the column of fluid coul 1 be absorbed, so the heat 

 of each day would build up a higher vertical tube, and capillary 

 attraction would account f ot the co . ! . r fluids produced at night 



or rising from the root filling the vessels to their extremities. It 

 seems to me, therefore, that the work done in lifting vegetable 

 matter to the apex of a plant is due to the increase of heat in the 

 daytime ; that then the watery particles are evaporated, and the 

 solid left deposited in the form of cylindrical vessels of smaU bore. 

 In animals the prostrate posture of rest allows of growth without 

 thedifficultyof resisting gravitation; it is well known that deficiency 

 of sleep (perhaps more accurately of rest) stunts the growth of 

 animals, and that illnesses which keep children in bed during 

 their years of growth almost always cause a rapid increase of 

 stature ; surely this arises from the newly-formed tissues having 

 no gravitation to overcome, and therefore developing rapidly. 

 Probably if a child were taught to take rest in a vertical position, 

 it would not grow tall, but develop in breadth. 



The work done in increasing the stature of plants every year 

 must be enormous ; in one summer thousands of tons of vegetable 

 tissue must be raised through heights varying from a few inches 

 in an oak, to twenty or thirty feet in a hopbine, and much more 

 in a lliano, or tropical creeper. I presume in winter the cold 

 constricts the vessels, and so prevents sap from rising, hence 

 there is no growth at that season. 



Taunton College School II. P. Knapton 



Chemical Notation 



In Mr. Pattison Muir's very interesting article on thermo- 

 chemical investigation (Nature, vol. xx. p. 8, I find the fol- 

 lowing : — 



" That system of notation which is now employed in chemistrj', 

 although of the greatest value, is nevertheless far from being per- 

 fect ; it fails to tell anything concerning the changes in forms of 

 energy involved in those changes of distribution of mass (matter ?) 

 which it formulates." 



The author does not, however, propose any addition to the 

 usual notation for the purpose of indicating the transformations 

 of energy which take place in chemical transformations, yet this 

 may be done very simply. 



The symbol for water is HOJ. This states with perfect clear- 

 ness the fact that a molecule of water has been formed by the 

 combination of a molecule of hydrogen with a half molecule of 

 oxygen, but it leaves out of account the important fact that in 

 the act of their combination 34462 heat-units have been given 

 out. If we call a heat-unit 9, the symbol for water will then be 

 HOJ — 34462 $ ; the negative sign indicating that the heat has 

 hctn parted ■wilh. I propose to call such compounds thermo- 

 negative. Products of perfect combustion, such as water and 

 carbonic acid, are necessarily thermo-negative. 



There are thermo-positive compounds, of which protoxide of 

 nitrogen is one of the best understood. According to Fabre 

 and Silbermann, 1 1 54 heat-units are given out in the separation 

 from protoxide of nitrogen of one gramme of oxygen. It is 

 obvious that this heat must have been taken up in the formation 

 of the protoxide. Multiplying 1154 by 8 for the equivalent of 

 oxygen, we get 9232 as the thermal equivalent of the protoxide, 

 and we write its symbol NO -1- 9232 fl. 



Peroxide of hydrogen is usually written HO, but this, from the 

 point of view of chemical structure, is altogether wrong. Fabre 

 and Silbermann " estimate the heat evolved during the libera- 

 tion of one gramme of oxygen from peroxide of hydrogen at 

 1363 heat-units. Multiplying by 8 as before, we have I0904 as 

 its thermal equivalent, regarding it as a thermo-positive oxide of 

 water, and we write its symbol 



(HOi - 34462 e) -f Oi -t- 10904 e. 



Joseph John Murphy 

 Old Forge, Dunmurry, Co. Antrim, July 8 



Local Colour-Variation in Lizards 



Mr. Henry Hillyer Giglioli remarks (Nature, vol. xix. 

 p. 97) that the common lizard (Podarcis mtiralis) constantly pre- 

 sents dark varieties on islets adjoining small islands. A similar 

 case has come under my observation in the herpetological fauna 

 of this country. Amciva (cnemidophorus) vulgaris, Licht., is 

 very common all over Venezuela, and though it varies consider 

 ably in colour, it is, on the mainland, never black, as on the 

 small islands of Los Roques and Orchila, which lie a short dis- 

 tance off our Caribbean coast. Both islands have rather exten- 

 sive sandy beaches, covered with a very scanty vegetation, so 

 that, mutatis mutandis, they are, in the very words Mr. Giglioli 

 uses when speaking of Filfla, painfully white in the glaring 



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