TRANSACTIONS OF SECTION I. 829' 



9. The Psychic Development of Young Animals and its Somatic Corre- 

 lation, loith special reference to the Brain. By Wesley Mills,, 

 M.A., 2[.D., &c., Professor of Physiology in McGill University,. 

 Montreal. 



This Paper is founded on the previous one, and a series of investigations made 

 on the psychic development of young animals, and is an attempt to correlate tlie 

 results. 



10. The Physiology of Instinct. By Professor C. Lloyd Morgan, F.G.S. 



11. Tlie Nature and Physical Basis oj Pain. By Professor L. Wither. 



12. The Action of Glycerine on the Tubercle Bacillus. jBi/ S. Moxckton" 

 CoPEMAN, M.A., M.D. (Cantab.), and F. R. Blaxell, M.I). (Bond.). 

 (From the Bacteriological Laboratorj' of "Westminstpr Hospital Medical School.) 



.4.t the last meeting of the Association, held at Liverpool in 1896, a report on 

 the influence of glycerine on the vital activity of certain micro-organisms was pre- 

 sented to this Section. In that Paper we showed that the presence of glycerine to 

 the extent ot 40 per cent, in culture media, such as peptone beef broth, sufficed to 

 kill out, in various periods of time, certain pathogenic microbes, including the 

 Pf/ogenic cocci, Streptococcus Pyogenes, Streptococcus Erysipelutosiis, Bacillus- 

 Tuberculosis, B. Typhosus and B. Diphtlierire , the maximum resistance being over- 

 come in about three weeks. On the other hand, the spores of the common Hay- 

 Bacillus were shown to be capable of resisting the action of glycerine considerably 

 longer, as also was the B. Coli Comtminis when kept at low temperatures. 

 Samples of small-pox and vaccine material, in the form of lymph and ' crusts,' 

 were also employed, and were found to have become freed from extraneous micro- 

 organisms within comparatively short periods, when exposed to the influence of 

 40 per cent, glycerine. 



During the past year we have instituted furtlier experiments in this direction, 

 working especially witli the Bacillus Tuberculosis, with the object of determining 

 ■whether this micro-organism can survive and remain capable of further develop- 

 ment after a sojourn, for varying periods, in glycerinated vaccine lymph. 



Method. — Vaccine material was rubbed up in the usual way with a mixture 

 of glycerine and water, the greater part of the resulting emulsion (containing 

 glycerine to the extent of 42 per cent.) being then filled into small tubes. To the 

 residue, amounting +o about 4 c.c, was added a large quantity of growth from a 

 recently isolated and virulent culture of Tubercle Bacilli. This growth was 

 thoroughly mixed with the emulsion, and the whole was poured into two small 

 tubes, which were corked and placed in a cool, dark cupboard with the rest of the 

 tubed emulsion. At the same time, from the tubercle culture, control inoculations 

 were made in tubes of 6 per cent, glycerine agar-agar, and in tubes of 6 per cent, 

 peptone beef broth. These were incubated part at body temperature, and part at 

 that which ordinarily obtained in the laboratory. At the end of a month the 

 emulsion was demonstrated by the method of plate cultivation to be free from 

 extraneous microbes. Similarly plates poured from the small tubes containing the- 

 tubercle culture also showed no growth. Numerous inoculations were made on 

 the surface of G per cent, glycerine agar, and on solidified blood serums, the tubes- 

 being then incubated at 37° O. After a month's incubation, no growth resulted 

 from any of these inoculations. 



Lest traces of glycerine carried over by the inoculation needle should have- 

 retarded or prevented the growth of the Tubercle Bacillus, some of the emulsion 

 originally contaminated with tubercle was mixed with sterile beef-broth, and from. 



