LINNEAN SOCIETY OF LONDON. 23 



111 one section of this field of study man long remained less 

 successful. The blights and murrains of crops and herds have 

 always been matters of concern. Dominated by a hypothesis 

 which obscured the issue, man once strove to avert such attacks 

 by propitiatory rites which might include the congenial task of 

 slaying his neighbour, or the awkward duty of sacrificing his 

 offspring. As experience brought enlightenment measures of 

 precaution were devised. The i-easons for these were not always 

 appreciated by the crowd. This difficulty was overcome, and the 

 observance of the necessai'y measures ensured, by their incorpora- 

 tion in the ritual of religion. Assured in later days that ' the 

 law had been fulfilled,' man felt it right to sit with folded hands, 

 and to regard such visitations as signs of divine displeasure against 

 which it were blasphemy to murmur and impiety to contend. 



To us has come a new understanding. We now assume that 

 ' heaven best helps those who strive to help themselves,' and cope 

 with our blights and murrains by direct defence and flanking 

 counter-attack. But in our efforts to mitigate the harm that 

 pathogenic organisms cause, success depends on the extent to 

 which we ado])t the principles that guided early man when dealing 

 with dangers he could comprehend. Diagnosis and treatment ax*e 

 only satisfactory when we have established the identity and 

 mastered the life-history of these organisms. 



Even in this portion of natural history the faculty of observa- 

 tion and the instinct for experiment permitted early man to lay, 

 without knowing it, a sure foundation for future work. He 

 learned to control the preparation of substances that assuaged his 

 thirst and at the same time made his heart glad. The philosophical 

 study of the technique of that achievement has added a new 

 chapter to our science. If this increase in knowledge may not 

 always have improved the quality of what is set before us ' when 

 we take our ease in our inn,' we are none the less grateful to those 

 who have afforded the surgeon assurance that his wounds need no 

 longer become corrupt, and have enabled the physician to contend 

 against ' the pestilence that walketh in darkness.' 



Primitive rural economy was at first differentiated into occupa- 

 tions comparable with the two branches of natural history that 

 our Society cultivates. The amity which distinguishes our pro- 

 ceedings has not always marked their mutual intercourse. The 

 ' keeper of sheep,' whose to-morrows were so often occupied with 

 search after new pastures, may well have disturbed the ' tiller of 

 the soil ' who had fixed his abode and set limits to his fields. 

 But the dispute wliich culminated in an ancient tragedy had an 

 extrinsic origin. The merits of that case we need not discuss ; 

 the narrative may owe something to the inspiration of a priest- 

 hood which was not vegetarian ; it contains nothing offensive to 

 the susceptibilities of a race with a pastoral ancestry. 



In our latitudes such conflict of interest as may have taken 

 place proved capable of adjustment. Among us the two crafts 

 have long been carried on side by side ; many of our husbandmen 



