SCIENTIFIC NE^A7'S. 



[March ist, 18S7. 



THE CANAL THROUGH THE ISTHMUS 

 OF CORINTH. 



THIS year will, it is said, see the completion of the canal 

 through the Isthmus of Corinth. It is an ancient 

 engineering project that has lingered for ages, awaiting 

 the development of those mechanical and chemical sciences, 

 which have been the great characteristic of the present 

 century. It may indeed be called an ancient project, since 

 it is connected with the name of one of the seven sages, 

 Penander, who flourished 628 B.C. Penander, however, 

 was not able to overcome the superstitious opposition of the 

 priests. Demetrios Poliorpetes, King of Macedonia, about 

 300 B.C., also entertained the project of piercing the isthmus, 

 but failed to carry out his intention, because his scientific 

 advisers, anticipating the fallacy which arose when the Suez 

 Canal scheme bid fair to become realised, asserted that 

 the difference in the levels of the sea would offer an unsur- 

 mountable obstacle. Yet we find the Emperor Nero, with 

 all pomp and magnificence, actually commencing operations 

 himself with a golden spade. Thousands of slaves were 

 employed, among whom were 6,000 Jews ; presumably with 

 less costly tools. Nero's engineers must have been able 

 men ; some boreholes have been preserved to our days ; 

 and the Societe Internationale du Canal Maritime deCorinthe 

 has adhered to the line which these boreholes mark. The 

 final success of the scheme seems mainly due to the exer- 

 tions of an old Hungarian soldier of revolutionary fame, 

 Stefan Tiirr, who now lives with his wife, a granddaughter 

 of Lucien Bonaparte, at Isthmia, a place founded by him- 

 self. The canal will extend from Isthmia to Posidonia. It 

 will be four miles long, and shorten the passage from Venice, 

 Trieste, Brindisi, etc., to the Black Sea, by about two hun- 

 dred miles ; and from Marseilles, and other Mediterranean 

 ports, by about half that distance. The passage will, further, 

 be much safer, the dangerous promontories of the Greek 

 Peloponnesus being avoided. Operations commenced on 

 the 8th of April, 18S2. Eleven million cubic yards have to 

 be removed. In some places the hills rise to 240 ft., and 

 geologists will find a rich field when the territory becomes 

 more accessible to them. It is clear that Poseidon has not 

 in vain ruled there for centuries, for those rocks through 

 which the cutting has been made have experienced rougher 

 concussions than from dynamite and powder, which are at 

 work now. The cutting is made with high perpendicular 

 walls ; the miner — generally an Italian or a Montenegrin — 

 stands on a ridge scarcely more than a hand wide, having 

 a rope attached to an iron bracket above fastened round 

 his body, and works the ground away from underneath his 

 feet. The subjects of the two nations mentioned have taken 

 the main share in the rougher and more dangerous work. 

 Armenians are generally employed for the earth work ; 

 Greeks are hardly seen, unless in the offices, as doctors in 

 the hospitals, or in some other of the more sedentary pur- 

 suits. The dimensions of the canal are exactly those of the 

 Suez Canal, 72 ft. in width, 26 ft. in depth, below the 

 deepest water level. The railway from Athens to Corinth 

 crosses by a bridge at the highest point, 300 ft. above the 

 water. The costs of maintenance are expected to be small, 

 since there is no danger from sand, nor from rapid erosion 

 of the vertical walls, which mainly consist of hard rocks. 

 The company has risked thirty-five million francs 

 (;^i,4oo,ooo), and intends to levy a toll of one franc per 

 ton for vessels from the Adriatic Sea and half that sum for 

 other ships ; each passenger to pay one franc. Mr. Eduard 

 Engel has recently visited the works, and we are indebted 

 to his interesting pamphlet, " Griechische Fruehlings-Tage," 

 just published, for these particulars. The rapid strides 

 which the Greek mercantile marine has made in the last 



years, promise well for the future of the canal ; at the end 

 of 1885, the Greek mercantile marine ranked already 

 eleventh, with 3,215 vessels, among which were 72 

 steamers. 



The Presence of Dissolved Salts in Vapours. — That 

 some liquid particles are mechanically carried away from a 

 liquid when violently boiling, is evident. That a certain 

 quantity of solid substances in .solution (such solids as are not 

 supposed to be volatile) will evaporate with the liquid at all 

 temperatures, has also been demonstrated by M. Marguerite 

 Delacharlonny. He experimented with solutions of sul- 

 phuric acid, caustic soda, and sulphate of iron. Laboratory 

 tests showed the presence of these bodies in the vapours 

 given off after two and three days. Experiments were then 

 arranged on a larger scale, with sulphate of iron and alum. 

 Test papers impregnated with litmus and helianthin were 

 suspended above, and after two or three days the papers 

 turned colour, the colour being uniform, not spotted, as 

 would be the case from any solid particles accidentally car- 

 ried over. The observations may be interpreted in a two- 

 fold way. Many bodies, not generally regarded as volatile, 

 are so to a very slight extent. Copper may belong to these, 

 as its smell would indicate. Others not volatile in them- 

 selves become so when dissolved in and together with cer- 

 tain liquids, and use is made of this peculiarity for separat- 

 ing cer lain bodies from one another. 



Saccharin. — The method now published for manufactur- 

 ing the new sweetening agent saccharin, or anhydroortho- 

 sulfaminbenzoic acid, the invention of Dr. Constantin 

 Fahlberg, of New York, will hardly tend to increase the fears 

 of the ordinary sugar manufacturer. The inventor starts 

 with toluene, one of the many constituents of coal oils ; 

 treats it with concentrated sulphuric acid, converts the sul- 

 phonic acids obtained into the calcium, then into the sodium 

 salts ; mixes the dry sodium salts with trichloride of phos- 

 phorus and passes chlorine gas over the mixture. The next 

 step is to remove by distillation the resulting phosphorus 

 oxychloride, and separate the two sulpho-chlorides by 

 centrifugation, the para product crystallising whilst the ortho- 

 product remains liquid. The latter is transformed into a 

 sulphamide by means of dry ammonia gas or carbonate of 

 ammonia, purified by washing with water and oxidised in 

 a solution of permanganate of potash. This latter operation 

 requires great care ; the potash salt so obtained has then 

 only to be decomposed to yield the free acid, the saccharin, 

 in white crystals, soluble with difficulty in cold water, but 

 easily in hot water. The process looks somewhat compli- 

 cated ; and as sugar is now so cheap, saccharin does not 

 appear to be a very formidable rival, even if its pleasant 

 sweet taste is perceptible in solutions of one in 10,000 parts 

 of water, and if A. Stutzer is right in asserting that the con- 

 tinued use of saccharin is not accompanied by any injurious 

 effects. 



Polarisation of Resistance Coils. — Last autumn, at 

 the Buffalo meeting of the American Association of Science, 

 Professor Mendenhall drew attention to a peculiar polarisa- 

 tion, of which all his resistance coils seemed to suffer, and 

 which he believed to be of statical nature. Professor 

 Benjamin Thomas then examined his coils at Columbus, 

 Ohio, with the help of a Thomson astatic galvanometer 

 made by Elliott Brothers. With the exception of one 

 B A coil, made by the same firm, they all gave a polarisa- 

 tion deflection ; and it was noticed that the wire terminal, 

 which was positive during charge, was again positive during 

 discharge. The polarisation effect was further a steady, 

 though of course faint, current, remaining observable in one 

 instance for ten hours. An experimental coil of 1,800 



