SCIENCE. 



FRENCH ACADEMY OF SCIENCES. 

 Nov. 7, 1 88 1. 



Action of cold on the voltaic arc. — According to M. 

 D. Tommasi, the voltaic arc is considerably enfeebled if, 

 by means of a current of water, the electrodes between 

 which it is produced, are cooled. Its brilliancy is then 

 not intense and the least breath extinguishes it. Its tem- 

 perature also is relatively but little elevated. These facts 

 are evident a priori. The magnet displaces and extin- 

 guishes it. It is the same on the approach of an inflam- 

 able body. 



Molecular Physics. — M. Fizeau sent a communication 

 relative to the variation in length of a bar of zinc brought to 

 an even temperature after having undergone different ac- 

 tions. The application which these facts will receive is 

 immediately seen in point of view of the construction of 

 metallic measures. 



The accents of the deaf and dumb. — It is known that 

 the deaf and dumb can be taught to speak so that we can 

 converse with them very nearly as well as with men who 

 have possession of both of these senses. M. Felix He- 

 ment announces the fact that the individuals who can 

 thus speak, are affected by the particular accent of their 

 native province. As they have not acquired this accent 

 by imitation, since they are deaf, the author thinks that 

 the reason must be sought in the arrangement of the pho- 

 netic apparatus, special to each race. 



Mechanics. — It is in a special way that M. Bertrand 

 announces a memoire by M. Levy, relative to the trans- 

 portation of force to a distance by electricity. It is known 

 that calculus demonstrates that a 16 horse-power engine 

 can transmit force to a distance of 10 to 50 kilometres. 

 M. L6vy states that a much superior result can be ob- 

 tained. 



INFECTED PORK. 



It is not only Trichinae which is to be dreaded in the 

 hams exported by the United States ; in one of the re- 

 cent meetings of the Medical Congress, Dr. E. Ballard 

 and Mr. E. Klein called the attention of the public to an- 

 other still more dangerous parasite in the same meat. The 

 Journal of Hygiene makes the following remarks on this 

 subject : 



In 1880, on the estates of the Duke of Portland, at 

 Welbeck, twenty persons were taken seriously ill, after a 

 dinner in which boiled ham had been served, with pork 

 imported from America. Four persons died ; others felt 

 no evil effect. The morbid symptoms showed nothing 

 very characteristic (choleric diarrhoea, vomiting, pains in 

 the muscles, great prostration); the autopsy only revealed 

 pulmonary congestion. In a piece of kidney, examined 

 under the microscope, there were found traces of inflam- 

 mation of the parenchyma, and in the capillaries of the 

 Malpighian tufts, incrustations formed by masses of 

 Bacilli. 



In passing over the field of the microscope, particles of 

 the raw ham and of the boiled ham which was infected, 

 a species of Bacillus with its spores was found ; the bacil- 

 lian threads and the spores adhered closely to the muscu- 

 lar fibres and to the intermuscular tissue. 



Experiments were made on animals: 1. By feeding 

 and by inoculation, or by the two methods combined. 2. 

 By inoculation after cultivation of the bacillary matter in 

 the incubator. In every case sickness was caused, and at 

 the autopsy, lesions of pneumonia or pulmonary hemorr- 

 hage were established. 



A second series of observations was made on fifteen per- 

 sons who felt serious symptoms after having eaten a leg of 

 pork, roasted in the oven, bought at a second-class cook- 

 shop. One of them having died, Bacilli were found, at 

 the autopsy, in the blood of the heart, in the blood pressed 

 out of the pulmonary tissue, and in the blood extravasated 

 around the pulmonary alveoli. The tissues of the 



stomach, the ileum, the spleen, and the kidneys, also con- 

 tained Bacilli. 



Experiment by inoculation with different liquids, on 

 animals, caused morbid and often mortal symptoms. 

 Bacilli were also found in the blood, and in the different 

 tissues of the animals. Unfortunately, in this case, the 

 suspected food could not be examined. 



In the face of these facts, Messrs. Ballard and Klein do 

 not hesitate to admit an acute specific affection, not to 

 this day defined, and presenting marked characteristics, 

 in point of view of the morbid phenomena, with the 

 known cases of poisoning by damaged or trichinated meat. 



Dr. Tripe, of London, recalled two febrile maladies 

 which he had observed in his medical circumscription. 

 In the first, sixty- six persons showed alarming morbid 

 symptoms, after a dinner in which sausage containing a 

 mixture of beef and pork fat, had been served. In the 

 second it was pork fat alone which was the immediate 

 cause of the sickness. Dr. Buchanan mentions cases of 

 diseases, in which beef and mutton constituted the in- 

 fected substances. — La Nature. 



THE COMPARATIVE ACTION OF DRY HEAT 

 AND SULPHUROUS ACID UPON PUTRE- 

 FACTIVE BACTERIA* 



Pieces of woolen and cotton cloths and wadding were 

 dipped in a solution of putrefying flesh and slightly dried ; 

 and after being shown to be infected by causing discolor- 

 ation and development of bacteria in a Pateur solution, 

 one portion was subjected to dry heat, and the other to 

 the influence of a definite quantity of sulphurous acid. 

 When these agents had operated for a certain time, the 

 substances were brought into a developing liquid and 

 again observed. 



These experiments, which were conducted by Dr. 

 Wermch, were. as follows : 



First. Fragments of the materials above referred to, 

 treated as mentioned and dried, produced in sixteen ex- 

 periments an exceptionably rapid disturbance of the test 

 liquid. In four experiments with wadding this was some- 

 what retarded. It took place most rapidly in tubes which 

 had been inoculated with woolen thread. 



Second. After inoculation with the material which had 

 been exposed one or two minutes to a dry heat of 284" to 

 300" F., clouding took place in four of eight experiments ; 

 but only after from two to three days. With material 

 which had been exposed from ten to sixty minutes to a 

 a heat of 230°-244° F., in five out of six experiments a 

 development of bacteria took place after the end of 

 twenty-four hours. 



Third. Substances which were exposed five minutes to 

 a heat of 257° to 302' F. produced no infection whatever 

 in ten experiments. The test liquid remained clear for 

 eleven days from the time of inoculation. 



Fourth. When the objects were exposed under a bell 

 glass to the action of a percentage, by volume, of 1.5, 2.2, 

 and 3.3 of sulphurous acid, in eight out of nine experi- 

 ments a bacterial clouding was developed in the sulphu- 

 rized material, whether the application had continued for 

 one hour or twenty-two. 



Fifth. In fifteen experiments, in which sulphurous acid 

 constituted 4.6 and 7.15 per cent, by volume, of the con- 

 tents of the bell glass, the introduction of the sulphurized 

 material produced no cloudiness, when the experiment 

 continued six hours and more. On the other hand an ex- 

 posure of 20, 40, 60, and 200 minutes was followed by the 

 development of bacteria. 



In conclusion, the fact was considered especially inter- 

 esting that the different fabrics gave up the infection con- 

 cealed in them with different degrees of rapidity, the 

 woolen fiber the quickest, the linen less easily, and the 

 wadding with the greatest difficulty of all. 



* From the proceedings of United States National Museum. 



