110 



KNOWLEDGE ♦ 



[July 1 i, 1882. 



the coasts of Spain and Africa until it rejoins the north 

 equatorial curn^nt caused l)y the Xorlh-easI trades." 



It we take tlie mean of the ditTerent estimates of the 

 magnitude of the Gulf Stream, as given by Maury, 

 Herschell, Colding, Croll, and Thompson, we shall find, 

 according to Haughton,* that nearly 38 (37-831) cubic 

 mi\os of warm sea-water are transferred from the tropics 

 to the north temperate zone per hour. This vast mass of 

 sea-wator leaves the tropics at a tempei-ature not less than 

 6.')" FalL, and is cooled down to at least 40° Fall, in the 

 temperate zone, ilaury estimates the rate of movement 

 at five knots an hour. Sir John Herschell at four, Croll at 

 four miles, and Sir Wyville Thompson! at three knots 

 an hour. 



We have seen that this enormous volume of sea-water 

 transfers heat from the tropics to the north teuipcratc zone, 

 and tlien gives forth 2'>' of the 6.5° F. which it contained 

 at its point of issue from the Straits of Florida. 



By the warmth thus brought from the southern latitudes, 

 the British climate is upwards of 120° warmer, writes 

 Buchan,+ in vittlcr than it otlierwise would be. 



Haughton, II in his paper on the effects of Oceanic currents 

 upon climates, published in the Report of the Britisli 

 Association for 1881 (York Meeting), has given much 

 interesting matter on this subject. He there insists that 

 the effect of the Gulf Stream upon our climate is limited 

 to the winter, and that its effect on the summer tempera- 

 ture is »i7. 



For instance, he shows that the mean temperatures of 

 •January and July, the coldest and hottest months of the 

 year, are as follows, taking the •")0° K latitude, which runs 

 through the Land's End, Cornwall : — The mean January 

 temperature at (Ivlf Stream lowfxtudeg is 4000° F., whilst at 

 all oilier loiijilrtd-s it is 1H-28°F., or 1372° beluw freezing- 

 point The mean Jul;/ temperature at Gulf Stream Jowji- 

 I'ldes (Lat i")©' N.) is 03-80° F., whilst rt< all other longitudes 

 it is 6-'r77° F., or lower by 1-97° F. ; and he concludes that 

 the (Julf Stream adds nothing to the July temperatures of 

 the localitie.s affected by it, but rather, on the whole, has 

 the effet-t of slightly diminishing the summer heat. The 

 general climatal effect of the Gulf Stream is, therefore, 

 to make the annxuil ranfje of temperature less ; (the climate 

 more insular), but it has no effect whatever upon summer 

 heat or upon the fruiting of plants and trees that require a 

 given July temperature for reproduction. 



The effect of the Gulf stream on the winter temperature 

 of our Seaside Health-Rcsorts is most marked, and by the 

 kind permission of Mr. Alexander Buchan, M. A., F.R.S.E., 

 whose able works on meteorology are now so well known 

 and appreciated, we shall be able to illustrate this most 

 important part of our subject by giving his charts of Iso- 

 thermals, together with tho.se promised in our last. It will 

 theu be clearly .seen how each Health-Re.sort is affected, 

 not only by the vnnter wnrmth of the sea, but by the sum 

 mer hnal of the sun — the one temperature being exotic, 

 whiUt the other is indigenmw. 



Ckvctat. PALAcr. — It in proponed by the Crystal Palace 

 authoritica to organise an exhibition in tbc coming antamn anil 

 winter, which shall inclodo both ffla and electric lighting. This is 

 an excellent moTC, and one in the right direction. The great diffi- 

 culty with which the anthoritieR will have to contend will, doubtless, 

 l>c the mntaat j-alousics now go openly paraded. 



• Op. ci>. 



^ "The Vi.yajfo of the Challenger: the Atlantic," vol. i., p. 371. 

 (Xncmillan, Undon.) 1877. 



J " Introductory Text Book of Meteorology," by Alexander 

 Bnchan, MA, F.R.S.K. (Blackwood, Kdinbnrgh.) 



i; p. 451. 



HOME CURES FOR POISONS.* 



VEGETABLE POISONS. 

 TT7E may leave mineral poisons for the present, to 

 >\ consider some which at the present season and 

 during the next few months are more likely to be mis- 

 chievous, .^viz., vegetable poisons. 



The most dangerous of these are the Hemlocks, including 

 Hemlock Dropwort (J-Jnanthe Crocala), Water Hemlock 

 (Cicuta Virosa), and the Common Hemlock {Conium 

 Macnlatum), Fool's Parsley (^Kilnisa Cj/nnpiitm), Monks- 

 hood (Aconitum Napellus), Fo.xglove (Digitalis J'ui-jmrea), 

 Black Hellebore or Christmas Rose {Ilellehorus Niger), 

 Buckbean (.Vcni/anlhes TrijnUata), Henbane (Ili/oscgamus 

 Niger), Tliorn Apple (Datura Stramonium), and Deadly 

 Nightshade (Atropa lielladonna), — to which may be added, 

 though unlikely to bo taken in the same way, Cocculus 

 Indicus (ilenispernum Cocculus), and Tobacco (Xicotiana 

 I'ahacum). 



The Hemlocks and Fool's Parsley are UmbelliJ'era; and 

 belong to the same order as carrots, parsley, celery, and 

 parsnips. They owe their danger cliielly to their resem- 

 blance cither in root or leaf to these kitc-Hcn-garden plants. 

 Fool's parsley in particular has often been eaten by mistake 

 for common parsley, from which, however, it may be readily 

 distinguished by the black and shining surface of the 

 under leaves, and their unpleasant smell when rubbed. 

 All these four plants produce similar symptoms (Hemlock 

 Dropwort in the most dangerous degree), viz., confusion of 

 ideas, often terminating in delirium or stupor, coldness of 

 the (ixtremities, and occasionally nausea and vomiting. 



Monkshood is a well-known garden plant, distinguished 

 by its dark-blue, cap-shaped flowers, growing in clusters on 

 a stem about three feet in height. The loaves are deeply 

 divided, the upper surface dark, glistening green, the- under 

 surface pale-green. The .symptoms produced are vomfting, 

 convulsions, delirium, and stupor. There is generally no- 

 ticeable swelling of the tongue and face, and tenderness of 

 the stomach. 'The poison acts chiefly on the nervous sys- 

 tem. According to Orfila, the juice of the leaves causes 

 death in a short time ; the root is still more energetic in 

 its action. 



Foxglove, though a wild plant, often finds a place in our 

 gardens. Everyone knows its tall stems, and the purple 

 flowers, shaped like a glove-flnger (whence its German 

 name, Jingerhut). The leaves are dark-green, and rough. 

 The symptoms of poi.soning by this plant arc lowering and 

 intermission of the pulse, faiiitness, giddiness, and cold 

 sweats, with hiccough and convulsion.s. The effect on the 

 circulation is characteristic of tlie action of Digitalis ; it 

 has been known to lower the pulse from 120 to 50 in a 

 few minutes. It al.so has a diuretic effect. 



Black Hellebore is a dwarf plant, with deep-green leaves 

 springing from the root. The flowers resemble those of the 

 dog-rose in the numljer and shape of their petals. The 

 symptoms are vomiting, giddiness, cramps, and convulsions. 



Bucklxjan, which is often gathered with the common 

 watercress, may be easily distinguished by th(! leaves, 

 which are always trifoliate, whereas the leaves of water- 

 cress are divided into five or seven segments. Buckbean 

 produces vomiting and colic, but seldom any serious 

 mischief. 



• It is perhaps hardly necessary to point out that for decoction 

 of tincture of Quinine in our last paper on this subject (p. 71, lino 7), 

 decoction or tincture of Cinchona (or Peruvian Hark) should bo 

 read. The correction should bo made in kHu, as iiIbo a few lines 

 further on, where Quinine is again, by a printer's error, substituted 

 for Cinchona. The decoction may 1)0 taken in doHCS rif a wine- 

 glassful, at intervals of from half an hour to un hour, or the powder 

 itself may l<e used. 



