12 



NATURE 



[Alay 2, 1878 



76°, depth 73° — during breezy temperature is 72°. A conferva 

 that is indigenous and confined to the lakes has been produced 

 in excessive quantities, so much so as to render the water 

 uawholesome. 



It is, I believe, Nodularia spumigera, allied to protococcus. 

 Being very light, it floats on the water except during breezes, 

 when it becomes diffused. Thus floating, it is wafted to the lee 

 shores, and forming a thick scum like green oil paint, some two 

 to six inches thick, and as thick and pasty as porridge, it is 

 swallowed by cattle when drinking, especially such as suck their 

 drink at the surface like horses. This acts poisonously, and rapidly 

 causes death; symptoms — stupor and unconsciousness, falling 

 and remaining quiet, as if asleep, unless touched, when convul- 

 sions come on, with head and neck drawn back by rigid spasm, 

 which subsides before death. Time — sheep, from one to six or 

 eight hours ; horses, eight to twenty -four hours ; dogs, four to 

 fire hours ; pigs, three or four hours. 



A post mortem was made on a sheep that had thirty ounces of 

 fresh scum administered by the mouth : death was long coming 

 on— about fifteen hours; examination made six hours after. 

 Stomachs : none of the green scum left, all absorbed ; dry grass 

 food in stomachs. Abdominal cavity contained two pints of 

 yellow serum ; heart flaccid, but not pale ; great effusion of 

 serum around it. Lungs, liver, kidneys, and substance of brain 

 healthy and normal, but the dura mater congested. Blood 

 throughout veins and arteries and in both ventricles black and 

 uncoagulable, neither did it become scarlet on exposure to the 

 air. Many sheep that died, on being opened, presented the 

 same appearances, all being without any sign of its presence in 

 the stomachs. 



This shows that the plant is rapidly absorbed into the cir- 

 culation, where it must act as a ferment and cause disor- 

 ganisation. The cattle will not touch the puddles where the 

 scum has collected and gone putrid. Thus all they take is quite 

 fresh, and the poisoning is not caused by drinking a putrescent 

 fluid full of bacteria as at first supposed. When this scum col- 

 lects on the banks and is rapidly left dry, it forms crusts of a 

 green colour. This has gone out of the Murray mouth into 

 the ocean and been wafted ashore, forming thick beds of green 

 stuff from a few inches to twelve inches thick. When, how- 

 ever, this scum is left in wet pools and puddles it rapidly de- 

 composes, giving off a most horrid stench like putrid urine, or 

 archil in process of manufacture; but previous to its getting 

 into that state it emits the smell of buytric acid, smelling like 

 very rancid butter. 



There exudes from this decomposing matter a blue pigment 

 which has remarkable properties. Sample tube i contains the 

 fluid as strained off from the scum and will be found full of 

 bacteria. No. 2 is the same with glycerine, and filtered to sepa- 

 rate the bacteria. 



This fluid- is remarkably red, fluorescent by reflected light, 

 being blue by transmitted light. Spectrum a broad and deep 

 band total at top in the red, but shading off to green, quite 

 cutting off orange and yellow. 



Chemical properties :— Heat destroys colour; sulphuric acid 

 no action ; nitric acid reddens ; hydrochloric acid, the alkalis, 

 and ammonia, destroy colour ; chlorine and ozone bleach ; 

 light but little action, yet sunlight gradually bleaches ; dries to 

 a mass, retaining colour ; soluble in water, glycerine, and weak 

 alcohol. I think this is allied to the colouring matter of some 

 lichens, is a product of decomposition, and not pre-existing in 

 fresh plants. Its fluorescent powers are remarkable, and the 

 most powerful I have ever met with. George Francis 



Adelaide, S. Australia, February 11 



Transmission of Vocal and other Sounds by Wires 



The following are notes of- some additional experiments 

 since those recorded in my paper laid before the Physical 

 Society of London, an abstract of which appeared in Nature 

 of 25th inst. 



1 . An ordinary iron fence railing was selected containing six 

 lines of wires varying from f\ to \ inch in thickness. These 

 wires were passed through iron supports at every two yards. A 

 disc, mouth and ear- piece, was attached to one of the wires 

 when speaking, singing, whistling, and breathing were trans- 

 mitted through distances varying from twenty to sixty yards, 

 whilst the sound of a small tuning-fork was heard at 100 yards. 



2. In an iron fence, with heavy iron top-rail, half inch square 

 in section, and having iron supports at rjery yard, it was found 



that the above-mentioned sounds could be transmitted through 

 about thirty yards ; the tuning-fork sound, however, was heard 

 at sixty-six yards. 



In the latter experiment the best results were got with a 

 hollow wooden mouth-piece, pressed against the iron, the ear 

 being connected with the iron by means of a solid body, such as 

 a cork. 



3. Some yards of No, 16 copper wire were attached to the 

 ordinary bell-wire connection from one room to another ; 

 another portion of the same copper wire was attached to the 

 brass bell crank in asother room — a lobby intervening ; — speak- 

 ing, singing, and other sounds were readily transmitted ; the tone 

 was low, but clear. 



For this experiment the terminal discs were of pasteboard, 

 set in metal rims. 



In the experiments with the iron fence, the sounds were free 

 to pass not only up and down the particular wire selected, thus 

 necessarily doubling the range of distance given above, but 

 suffered breaking up at each support, and consequent distribution 

 through the other wires. 



Glasgow, April 27 W. J. Millar 



Westinghouse Brake 



The experiment shown by the Westinghouse Brake Company 

 was described by Sir W. Armstrong as long ago as 1843, in a 

 paper " On the Efficacy of Steam as a Means of Producing 

 Electricity and on a Curious Action of a Jet of Steam upon a 

 Ball " {Phil. Mag. xxii.). The explanation of the phenomenon 

 as due to the centrifugal force of the diverted jet is given in 

 general terms in Young's "Lectures on Natural Philosophy" 

 (Lecture xxiv. p. 297). R. « 



April 28 



The Oxford Commissioners' Statement 



May I be permitted to draw attention to the very marked 

 discrepancy between the arrangements proposed by the Uni- 

 versity of Oxford Commissioners for the Animal and for the 

 Vegetables side of Biology ? Assuming, as we fairly may, that 

 by ' ' Physiology " the Commissioners mean Animal Physiology, 

 and supposing — what is by no means improbable — that the future 

 Reader in Invertebrate Anatomy would refuse the Professorship 

 of Zoology ; when that office is next vacant, we see that there 

 would he four University Professors (or Readers) of Animal to 

 one of Vegetable Biology; while we may also note that at 

 Christ Church there is a Reader in Anatomy, and that at no 

 College is there any Reader in Botany. 



When the efforts, which may fairly be described as violent, 

 to effect the removal of the Botanical Gardens to a peculiarly 

 objectionable site failed, it was hoped that those who, wittingly 

 or unwittingly, endeavoured to paralyse the study of Botany in 

 this place, would have yielded fairly. 



The suggestions now made lead us to fear that the Commis- 

 sioners have been persuaded to do what the University would 

 not do. 



At any rate, if the matter is too delicate for the Professor of 

 Botany to deal with, it is to be hoped that other Botanists will 

 make proper representations to the University Commissioners. 



April 27 B« 



Contact Electricity 



If a Volta's condenser be formed of an iron and a copper 

 plate having their surfaces of contact well ground together, it is 

 found that, on placing them together and then separating them, 

 the iron acquires a positive charge and the copper a negative. 

 This occurs so long as the atmosphere surrounding the plates is 

 the ordinary one containing watery vapour and other oxygen 

 compounds. But if the atmosphere contain sufficient hydrogen 

 sulphide, the iron will be found negatively and the copper posi- 

 tively electrified. Sir Wm. Thomson has shown that "a metal 

 bar insulated so as to be movable about an axis perpendicular 

 to the plane of a metal ring made up half of copper and half of 

 zinc, the two halves being soldered together, turns from the zinc 

 towards the copper when vitreously electrified, and from the 

 copper towards the zinc when resinously electrified." 



Substituting for the zinc half of rirg an iron half, the same 

 effect takes place, but in a less degree ; but if the ring be 



