August 8, 1890.] 



SCIENCE. 



n 



another, and an enclosure taking in an area to the south and west 

 of it. The lowest wall of all — 38 feet 8 inches thick, and formed 

 of clay bricks, unburnt — is believed to be that of Lachish, the 

 ancient Amorite city, erected probably 1500 years B.C. Phoenician 

 pottery of about 1100 B.C. is found above its level. Later con- 

 structions are the supposed wall of Rehoboam, and remains of the 

 fortifications made in the reigns of Asa, Jehoshaphat, Uzziah, 

 Jotham, and Manasseh. The pottery discovered on the spot is 

 very valuable. " We now know for certain," says Mr. Petrie, 

 " the characteristics of Amorite pottery, of earlier Jewish, and of 

 later Jewish influenced by Greek trade, and we can trace the im- 

 portation and the influence of Phoenician pottery. In future all 

 the tells and ruins of the country will at once reveal their age by 

 the potsherds which cover them." 



— The Brooklyn Medical Journal quotes from a German author- 

 ity the following review of the physiological effects of saccharin, the 

 new sweetening agent. According to the investigations of Plugge, 

 a .03 per cent solution of saccharin entirely destroys the action of 

 ptyalin, and hinders the action of pepsine and pancreatine. On 

 this account it is injurious to diabetics, to whom a good digestion 

 is very important. On the other hand, E. Gans, Stevenson, and 

 Wooldrige express the opinion, based upon their experiments, that 

 saccharin is not injurious to the digestive processes, but it hinders 

 the secondary decompositions of the contents of the intestinal 

 canal. The Royal Academy of Medicine at Madrid has given the 

 opinion that the addition of saccharin to foods and drinks should 

 be regarded as an adulteration, and that articles of food, or drink, 

 so treated should be refused entrance into Spain. A similar judg- 

 ment has been given by the Academy of Medicine at Rio de 

 Janeiro. France has adopted laws forbidding its use in foods. 



— The British Vice-Consul at Los Angeles, California, in a late 

 report, has some observations on the vine and orange pests in that 

 region. As summarized in Nature, the report states that the 

 vine disease now seriously menaces the existence of the viticul- 

 tural industry in the vicinity of Los Angeles. At first it attacked 

 chiefly the "mission" vines; now, other varieties of red vines are 

 dying, and the white varieties are also suffering. The disease 

 first appeared in its present dangerous form in the southern part 

 of California, and destroyed many vineyards. Professor Dowlen, 

 an expert employed by the Viticultural Commission to ascertain 

 its cause, and, if possible, discover a remedy, inclines to the 

 opinion that it is due to a fungus. On the other hand, Mr. 

 Wheeler, Chief Executive officer of the Viticultural Commission, 

 reports that he is fully convinced that the fungus found on the 

 dead vines is not the prime cause of their decadence, and that it 

 attacks them only when they have been weakened by other causes. 

 As to the Icerya. or " white scale," which has ravaged the orange- 

 groves, the Vice-Consul says that a year ago many of the principal 

 orange-growers in the vicinity of Los Angeles had abandoned their 

 efforts to exterminate this pest, concluding that their trees must 

 die. Fortunately, it was learned that an Australian parasite, the 

 VedoHa cardinalis, had exterminated the white scale in Australia. 

 A colony of the bugs was imported, and placed on the trees in an 

 orchard in Los Angeles. They multiplied so rapidly that in a few 

 months the scale was entirely exterminated in the district, and 

 many trees which a year ago were nearly dead, have revived and 

 borne half a crop this season. 



— In a recent article on slag cements, a French authority, as 

 quoted in a recent issue of Engineering, states that these cements 

 are made by finely grinding blast-furnace slag, and mixing it with 

 a suitable proportion of fat lime. The grinding has to be very 

 fine, because as the cement is made by a simple mixture it is 

 necessary that the surface on which the two constituents, the lime 

 and the slag, react on each other should be as large as possible, if 

 proper chemical combination is to ensue. As manufactured in 

 France, the cement leaves only 20 per cent on a sieve containing 

 upwards of 25,000 meshes per square inch, and only 8 to 10 per 

 cent on a sieve with 4,500 meshes per square inch. The density 

 of slag cements is much less than that of Portland, weighing bulk 

 for bulk, but from .8 to .88 times as much. In general, this 

 cement also sets somewhat more slowly than Portland, but when 

 hardened, has, in many cases, a greater strength, particularly at 



early dates after setting. In some experiments still unfinished, 

 the following results were attained with a slag cement from the 

 Department of Isere: 



Age 1 week, 1 month, 3 months. 



Breaking load, povinds per square inch 473.5 568.8 678.3 



These figures are higher than any attained in the tests made on 

 Portland cements for the new Croton aqueduct. Experiments 

 were also made with slag-cement mortar mixed with and allowed 

 to harden in sea-water, and gave the following results; the mortar 

 consisted of six parts by weight of cement to ten of sand. 



8 days. 



Breaking Weight, Pounds per Square Inch. 

 252.0 319.9 275.1 273.0 285.8 



375.4 327.0 327.0 248.4 341.2 



The main objection to slag cement seems to be that if it is allowed 

 to harden in dry air its strength is very materially reduced, and it 

 is then liable to crack. In the town of Villefranche-sur-Saone it 

 has been largely used for paving foot-paths. 



— The dangerous overcrowding of the London cemeteries has 

 been often commented on by the medical press of that city, says the 

 Medical Press, but the evil remains almost wholly unabated. The 

 Sanitary Committee of the London County Council has reported 

 that no time should be lost in closing burial grounds such as the 

 Brompton, which contains 155,000 bodies, and the Tower Hamlets 

 Cemetery, with its 347,000 bodies crowded into only seventeen 

 acres. The average grave is seven by three feet, and contains 

 eight adults and fourteen children, the covering of earth being 

 about one foot. In one instance, a committee of inquiry regard- 

 ing this cemetery found eighty infants in a grave or trench of less 

 dimensions than that of the average grave. There are twenty-one 

 burial places, with a total extent of less than three hundred acres, 

 holding a million and a quarter of bodies. The soil in most of 

 these places is clay, and the process of decomposition goes on so 

 slowly that bodies buried for a dozen years remain remarkably 

 well preserved. 



— The use of preservatives for articles intended for food and 

 drink is an important one, both for the manufacturer and consumer, 

 says the Brooklyn Medical Journal. From a sanitary point of 

 view, it is doubtful whether any of the preservatives ordinarily 

 added to articles intended for human consumption ought to be 

 encouraged. Laws exist in Continental European countries pro- 

 hibiting the use of certain of these preservative agents. Salicylic 

 acid is prohibited by most of them, and the manufacturers are 

 there beginning the use of benzoic acid, which is preservative in 

 small amount and is not easy to detect. After a discussion at a 

 convention of chemists at Speyer, Bavaria, on the 10th of Sep- 

 tember, 1888, the conclusion was reached that boric acid, as a 

 preservative for foods, is to be regarded with caution. Sanitary 

 authorities have generally spoken in stronger terms of the use of 

 boric acid, and yet it enters into the composition of a large number 

 of the preservatives in the market. Hirsehsohn gives a descrip- 

 tion of several different boro-glycerides which he recommends for 

 preserving foods. Boro-glycerine is prepared by heating glycerine 

 with boric acid, in the proportion of 124 of the former to 190 of 

 the latter. He also recommends sodium, calcium, and magnesium 

 glyceroborates. These compounds are mostly tasteless, and quite 

 soluble in water and alcohol. Magnesium borate is recommended 

 as a remedy in throat affections. A. R. Rosen recommends the 

 following method for preserving meats: Boric acid or its salts are 

 dissolved in water and the solution is then frozen. The article to 

 be preserved is then covered with this ice, with the result that the 

 meats are preserved after the ice melts. Dr. E. Polenske has 

 made an examination of ten commercial preservatives intended 

 for meats. Three of the ten contained sulphurous acid or sul- 

 phites; two contained borax, and five boric acid; one each con- 

 tained alum, arsenious oxide, salycylic acid, and free phosphoric 

 acid; two contained glycerine, and two boroglycerine; three con- 

 tained nitre, and six common salt. The one containing arsenious 

 oxide was the only one actively poisonous, but several of the others 

 was decidedly objectionable. Indeed, we should object to the 

 addition of anything to our meats which is not a natural in- 

 gredient of food or cannot be converted into a compound natural 

 to the human body. 



