INSTINCT AS A GUIDE TO HEALTH. 519 



organism has to undergo certain modifications, considerable in extreme 

 cases, and correspondingly less easy to undo. For every " second na- 

 ture" is, probably, a compromise with the persistency of untoward 

 conditions. Iron-workers become less sensitive, and at last rather par- 

 tial, to the fervid temperature of their workshops. Butchers, like the 

 North American Indians, and other carnivora, are apt to contract a 

 disposition which enables them to pursue their sanguinary vocation 

 with callousness, or something akin to satisfaction. Slaves become 

 sneaks, i. e., amateur flunkeys. The love of light, too often punished 

 with autos-da-fe, becomes a love of dusk, if not of darkness ; the Arian 

 skeptic subsides into a resigned Capuchin — Nature forbears to maintain 

 a hopeless struggle. For similar reasons, perhaps, she yields to the 

 persistent infatuation of the self-poisoners, called topers and opium- 

 eaters. Further resistance would imply chronic sea-sickness, and, 

 under the circumstances, an abnormal fondness for strong drink may 

 appear a lesser evil. Yet the characteristics of such propensities dis- 

 tinguish them clearly from a natural instinct ; they have to be artifi- 

 cially acquired, their importunity knows no limits, and their free 

 indulgence is always followed by a depressing reaction. Thus, even 

 in yielding, Nature remains true to her preordained laws. No one can 

 hope to evade their self-avenging rigor, though the mode of retribution 

 may take the unexpected form of chaining the miscreant to his idol, 



2. Abxormal Peeils. — The dangers incident to our artificial modes 

 of life seem now and then to deceive the foresight of instinct in a way 

 typified in the non-repulsiveness of certain mineral poisons. Nature 

 has taken ample precautions to secure her creatures against the poison- 

 perils of the upper world — hemlock, foxglove, and belladonna — but 

 failed to provide safeguards against such subterranean evils as arsenic, 

 or the social dangers yet slumbering in the womb of Time. Providence, 

 however^ may have foreseen that perils evoked by the potent hand of 

 Science could be avoided in the same way ; though the struggle for 

 existence may, in the course of time, evolve supplementary instincts. 

 Those fittest to survive, methinks, already begin to evince an intuitive 

 aversion to the sugar-coated poisons that have reduced our average 

 longevity to less than forty years. The world is getting prudent by 

 natural selection. The children of the twentieth century will not be 

 apt to overrate the nutritive value of fusel-oil. 



3. Parasitic Disordees. — The healing instincts of Nature, which 

 teach the surfeited brute to abstain from food, somehow fail to take 

 cognizance of the disorders caused by the agency of microscopic para- 

 sites, entozoa, etc. It has been suggested that the development of 

 such organisms is as foreign to the autonomy of the human system as 

 the growth of the mistletoe is to that of the oak, and thus escapes the 

 jurisdiction of its self-regulating laws. But a still more suggestive 

 circumstance is the fact that disorders of the class named reveal their 

 origin plainly enough to permit a direct removal of the cause, which, 



