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THE POPULAR SCIENCE MONTHLY. 



him that imparting the power " of repeating 

 classifications of animals with all the ap- 

 propriate definitions " had nothing to do 

 with communicating genuine knowledge. He 

 prepared a series of laboratory notes suf- 

 ficient for the dissection of a few plants 

 and animals, and used Huxley and Martin's 

 text-book, after it was published, as a lab- 

 oratory guide. The school board provided 

 eight Beck's students' microscopes, and, he 

 says, " we begin with the study of the to- 

 rula ; we then take in succession the follow- 

 ing organisms: protococcus, amoeba, bac- 

 teria, mold, stone-work, ferns, flowering 

 plants, infusorian fresh-water polyp, clam, 

 lobster, and frog. We devote to laboratory 

 one hour daily for seven months. At the 

 end of the course come morphological and 

 physiological generalizations. Our classes 

 number about eighty, and are divided into 

 working sections of sixteen each. The 

 average age of the students is sixteen years, 

 rather more than half of them being girls. 

 I have found the students eager and enthu- 

 siastic, and the large majority of them re- 

 gret the untimely end of their study of biol- 

 ogy," which is limited by the procrustean 

 regulations of the school-course. 



Natnre of Diphtheria-Poison. Drs. H. 

 C. "Wood and Henry Formad, co-operating 

 with the National Board of Health, have 

 been studying the nature of the diphtheritic 

 contagium. They began with inoculating 

 rabbits, under the skin or in muscles, with 

 diphtheritic membranes taken from the 

 throats of patients in Philadelphia. Not 

 diphtheria but tuberculosis followed as an 

 indirect and not a direct result of the inoc- 

 ulation, the relations between the two dis- 

 eases seeming to be only apparent. When 

 the false membrane was inserted into the 

 tracheas of the rabbits, severe trachitis was 

 produced, with an abundant formation of 

 false membrane, identical with that of diph- 

 theria. It was shown by further experi- 

 ments that the production of false mem- 

 brane involves nothing specific, but that any 

 trachitis of sufficient severity is accompanied 

 by it. The product differs from that of true 

 diphtheria oidy in its containing fewer mi- 

 crococci. Diphtheritic poison was next ob- 

 tained from Ludington, Michigan, where a 

 severe epidemic was raging. Inoculations 



with this matter, whether made under the 

 skin, in the muscles, or in the trachea, were 

 all followed by similar results, namely, a 

 quick affection, a rapid spread of the local 

 symptoms, and death ; and the blood, ex- 

 amined during life or after death, was found 

 to contain micrococci precisely similar to 

 those found in the Ludington cases ; and in 

 a few instances the plants were found in the 

 internal organs and the bone-marrow. The 

 urine of patients suffering from malignant 

 diphtheria is full of micrococci, and is even 

 more deadly in its effects than the mem- 

 brane. When cultivated, micrococci from 

 Ludington grew rapidly up to the tenth gen- 

 eration, and those from Philadelphia ceased 

 their growth in the fourth or fifth genera- 

 tion, while those taken from a furred tongue, 

 which showed similar shapes, never got be- 

 yond the third transplantation. The con- 

 clusion was drawn that the micrococci found 

 in ordinary sore-throat and those of diph- 

 theria differ only in their reproductive ac- 

 tivity. When rabbits were inoculated with 

 cultivated micrococci, diphtheria was pro- 

 duced with the second generation, but never 

 with any later product. Diphtheria may 

 be self-generated whenever conditions arise 

 within the body or act upon it from without 

 competent to stimulate the inert micrococci 

 in the mouth into active ones. 



Scientific and Popular Experiments 

 in Pathology. Mr. John Simon, D. C. L., 

 LL. D., in his address before a section of 

 the International Medical Association, on 

 " State Medicine," has forcibly presented 

 the duty of the state to facilitate and en- 

 courage scientific researches into the causes 

 of disease. All that wc know or can know 

 on this subject, he maintains, is and must 

 be learned by experiment. The experiments 

 that give us the teaching wc seek are of two 

 kinds : scientific experiments, carefully pre- 

 arranged and comparatively few, performed 

 in pathological laboratories, and for the most 

 part on other animals than man ; and " the 

 experiments which accident does for us, and, 

 above all, the incalculably large amount of 

 crude experiment which is popularly done 

 by man on man under our present ordinary 

 conditions of social life." Thus, in regard 

 to Asiatic cholera, we have the scientific in- 

 fection experiments of Professor Thiersch 



