Transactiorui. 1 3 



These microscopic germs were arranged in a class by themselves 

 under the name Schizomycetes, or splitting fungi, and were placed 

 between the algte on the one side and moulds on the other. They 

 were divided into four principal groups, viz. — micrococci, bacteria, 

 bacilli, and vibrios and spiral microbes ; but this like all other 

 classification, was only a matter of convenience, for in appear- 

 ance they closely resemble each other, and the dangerous ones — 

 2)athogenic — can scarcely be distinguished from the septic or 

 perfectly harmless ones. Having described several of the germs 

 and exhibited microscopic drawings of a number of them, he 

 referred to the multifarious modes by which infection can be 

 spread — by direct contagion, by infectious matter from diseased 

 persons escaping from sewers, <tc., being introduced into water, 

 foods, or articles used for culinary purposes, and by the inhilation 

 of vitiated air. He believed that before the disease was propa- 

 gated there must be certain conditions favourable to the growth 

 and development of the germ. For example, if seed were sown 

 on a macadamised road it would not grow for want of sufficient 

 nourishment ; but if in a cultivated field, it would liave all the 

 conditions favourable to its growth. In the case then of the germs 

 of disease, they must have tlie suitable iiidns or else perish. 



There are other conditions governing tlie spread of disease, such 

 as predisposition through weakness or other causes. Although 

 the germs of the different diseases liavo some tilings in common, 

 they do not always attack the system in the same manner, for 

 each disease has its own characteristic. The germ of diphtheria 

 (micrococcus diphtheriticusj attacked the throat, while those of 

 cholera and typhoid fever attacked the alimentary canal. 



In reference to their cure, the well-known axiom, "prevention is 

 better than cure," was all that he would then offer, but as to 

 how "to prevent" the disease he said — 1st. Limit the sphere of 

 action by complete isolation of tlie diseased ; 2nd. Fresh air, and 

 plenty of it ; 3d. Thorough disinfection. Having described a 

 number of experiments made with disinfectants, he recommended 

 chloride of lime as tlie cheapest and one of the best, but it had a 

 disagreeable odour, and was detrimental to colours, &c. Solu- 

 tions of permanganate of potassium were good, and could be 

 easily used, also carbolic acid, and the various powders contain- 

 ing it, and sulphur and sulplmrous fumes. One of the best was 

 a solution of mercuric chloride, but this was a deadly poison, and 

 he did not recommend it for that reason. In conclusion, Mr 



