SCIENTIFIC .AMERICAN SUPPLEMENT, No
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lO�O SCIENTIFIC .AMERICAN SUPPLEMENT, No. 651. JUNE 23, 1888. alloy with cop per, with which latt,er they formed orna has not been taken into account, Even this ?';1tlay, thing in the world to remember lllay just be among t,he mental metallic designs upon kmfe handles and such however, will not suffice to prevent a foul conditlOn of most difficult to B. We venture to aSSUllle, for lll things, and then released the dark-colored gold by a the river during the summer lI:lO�ths: The only o�her stance t,hat no chemical student would dream of try pickling process; by its means they h,ad produced an , feasi ble plan, in Sir Henry's 0pllllOn, IS,that of aeratlOn, ing to 'fix the date of the deluge ,in fÜS memory ?y so appearance of transparency in a metalhc representatlOn since free oxygen is to be had for n,othlllg, and the cost clmllsy a device as that we have JUS" q oted whll� he , � of water at a place where in the design a duck waR of pumping air need not be conslderable Sooner or has a far simpler plan always ready to hiS hand, as we represented plunging half its body below �he surface of later we shall have to filter the sewage through land, will endeavor to show. All he �eeds is the falllili1l;r a strealll, He believed that no other natIOn had made or discharge it into the estuary at a point not higher .. H,O," and this once thought of 10 the proper way" It use of this allo)', , than the sea reach, Until a more satisfactory means is simply impossible for it ever to be forg�tten, ,as m The changes which small proportions of f?reign mat for overcoming the evil has been devised, it is, proposed deed we have proved arnong our young fnends m nu- ter will produce in metals are not nece�sarlly o� small to add manganate in a moderate q uantity-three merous inst.ances. Thus: , , practical importance, for a sma�1 fractlOn o� ?Ismuth grains per gallon-during thobe periods of the year In "H,O" the central (and, therefore, most dlstmc in Cup per will reduce its electrlCal conductiv,lty �uffi when the dissol ved oxygen falls below,:W per cent, of tive) fact is the figure "2," cientlv to cause any submarine cable made wlth lt to the possi ble maximum, or the chlorllle exceeds 200 Of atoms, there are present exactly "3." " becouie a commercial failure, A cable made of �he grains per gallon , , Picturing the formula in our mind's eye as a f!ac, copper of to-day has twice as much message-carrYlllg Such is the gist of thiS valuable report, to WhlCh I,S tion, by the aid or an imaginary line of demarkatIOn, power as a cable made in the early days of telegraphy, appended full details of the experiments, the quanti HO , because of the copper now used belllg purer Pure ties of deo.dorants used, and the rainfall returns, -- we get 2 multiplied by 2 (elements) = "4." 16 17 gold has a breaking strain of from tons to tons to 2 , the square inch; but when alloy�d with but tu per Next, the division of the atomie welght of 0 (16) by , cent of lead it will break with a shght blow or I!nder a HINTS ON THE RELIEF OF TOOTHACHE,* this same figure 2. gives us "8," trifling strain, He next exhibited an alloy of ZlllC and THERE are four main causes of toothache : 1, irrita Lastly the forulUla itself-H,O-is permanently sug rhodium, which possessed in a small degree sOUle of the 2, 3, gestive �f the "deluge, " and the ,whoie ('Yh,ieh ?eeu properties of gun cotton, tion of the tooth pulp; exposure of the t,ooth pulp; periostitis; 4, alveolar abscess, or gum bO,lI. pies I1lUch more time and space m explamm� tt on ====== paper than is required for the mental effort) IS, once The first, irritation of the tooth pulp, IS ca�sed, as a DEODomZATION OF SEW AGE. rule, by caries, which starts at 8,ome c?ngemtal mal for all, indelibly impresse� upon the memory" , We could easily multlply examples of thls kmd, formation, and is aided by the varlOus aCids engende�ed FüR some time past, says a corr�spondent, of the in the 1tI0uth, the resllit of disease or of fermentatIOn tending to show that a chemist who knows his"sym Manchedter GttaTdian the metropohtan publtc have of particles of food lodged in 01' between the teeth, The bols and equivalents " fairly weil cau �herefrOlll con been anxious to get at ' Sir Henry Roscoe's report on the progress of the decay is no doubt also accelerated by struct for himself a far bettel' mneIlJOl IlC system than deodorization of metropolitan sewage at the outfalls, any he is likely to find elsewher�, various micrococci and cryptogamous growths, The At length a copy has fallen into my hand�, The re , ' " decay creeps on tiIl at last impr ss!ons or heat and cold Returning, however, to Dr PI,ck, hiS new m�thod port is exceedingly interesting, and of vast unportance t;l 18 or biting on a hard substance Irrltate t�e tooth pulp of improving the memory "-'YhlCl?, by t,he way, not to Londoners, It was a fortunate day that saw t�e and cause pain of a more or less severe kllld and dura- altogether novel-chiefly conslsts m takmg ad va,lltage appointment of Sir Henry Roscoe as consu�ting chemist tion, of the correlation of what Illay be terllled senes of to the Metropolitan Board of Works, Durlllg the shoI:t , , In this species of toothache, the dlagn?SIS could, be ideas, such, for example, as " book-printing ; printing time he has held that post he has accoml?lished a con arrived at by the following tests: no palll on tapplllg -newspaper ; newspaper-:-telegraph,; telegraph-At siderable amount of valuable work, SIr Henry ha;s lantic cable' cable-AllIel'lca; Amel'lca-cotton; co� the crown of the tooth, no redness round edge of the made several experiments in reference to the deodol'l gum and the pa in being only occasional and of a sharp ton-Manch�ster; Manchester-Sir Robert Peel; SIr zation which it will be as weil to set forth, A clear , char�cter, Telllporary relief would be afforded b� a Robert Peel-free trade," and so on idea df the principles upon which the deodorants stopping, such as cotton wool saturated wlth a solutIOn But here again different people would instinctively bleaching powder and manganate , of soda and sul . of mastic, 01' a plug of gutta percha to keep away c?ld forge very different links to the chain, wh<;n the whole phuric acid-act nlUst first be obtallled, as weil as the and pre�sure, with advice to have a permanent filhng "system ,. is at onee weakened, and the ttem wanted suhsequent changes whieh th� sewage undergoes ILf�er , , put in, would be missed and some other recalled to mel!JOry snch treatment in its passage lllto and adnll�ture w�th '['wws; The second variety, ruore frequently seen by pharllla Thus we might go easily frolll "newspaper " to the water of the river, No q uantity of chellllCals WhlCh cists, is ex posure of the pul p, The decay has proceeded times-clocks' clocks-watches; watches-Sir Joho ean be added is sufficient 1,0 change the whole of the , ' ' till it has laid bare the pulp cavity, �nd an)' ho or Bennett, etc; cable might sllggest "ship," 01 Sir R. � "bobbi6lS,"-Monthly Magazine. wlid maUer into harmless forms, sothat the use of chem cold substance or contact with any sohd matter brlllgs Peel, ieals is only to be regarded s a tem,porary measure, , � on an at.tack of severe toothache, �uided exclush'ely by conditlOns of tune and of plac�, This form oi toothache can be diagnosed by the Sir Henry points out that, considering the present THE ENEMIES OF THE HUMAN SPECIES, , P?SI severity and continuity of the pain of a sharp lall�inat. tion of the out falls, the arrangements now eXlstlllg RAPHAEL BLANCHARD, * ing description, and little or no inc ease of palll ,on By there and the conditions arising from drought and � percussion' it is generally accompamed by extensIve high temperature during the summer months, th� ad THE epoch in which we live will ever be memor�ble decay, and' the gum may have a red ring round the , dition of some deodorant to the effluent sewage IS ad in the history of human knowledge �t has preslded margin, visable' but should the conditions be altered, then the " over the birth of a goodly number of selences that were Relief in this case may be obtallled' by llltroduclllg necessity for such addition might decrease 01' �ven dis but yesterday unthought of, and, i� the first r�nk of, gently a plug of cotton wool saturated 'Yithcamp�or , appear, The use of chemicals is onl� ?f v�lue 10 �o far which stands microbiology Thls smence, of WhlCh the ated spirit camphorated chloroform,solutlOn of cocallle, that they either start a process of punficatlOo or sUllply illustrious Pasteur was the prophet, produced , a pro or any an�dyne of thfÜ description ; but of course these get rid of the evil odor, found perturbation in biology, and has revolutIOmzed , " , are only of a palliative description, and for permanent The knotty point is to purlfy the l'lve� (10 whleh the the physico-chemical world itself.