676 THE POPULAR SCIENCE MONTHLY. 



" The Italian naturalist, Filippi, discovered, in the blood of silk- 

 worms affected by this strange disease, p&brine, a multitude of cylin- 

 drical corpuscles, each of about ^Vo of an inch long. These have been 

 carefully studied by Lebert, and named by him Panhistophyton ; for 

 the reason that, in subjects in which the disease is strongly developed, 

 the corpuscles swarm in every tissue and organ of the body, and even 

 pass into the undeveloped eggs of the female moth. The French Gov- 

 ernment, alarmed by the continued ravages of the malady and the in- 

 efficiency of the remedies which had been suggested, dispatched M. 

 Pasteur to study it, and the question has received its final settlement. 

 It is now certain that this devastating, cholera-like pebrine is the effect 

 of the growth and multiplication of the Panhistophyton in the silk- 

 worm. It is contagious and infectious, because the corpuscles of the 

 Panhistophyton pass away from the bodies of the diseased caterpillars, 

 directly or indirectly, to the alimentary'canal of healthy silk-worms in 

 their neighborhood ; it is hereditary, because the corpuscles enter into 

 the egg. There is not a single one of all the apparently capricious 

 and unaccountable phenomena presented by the pebrine, but has re- 

 ceived its explanation from the fact that the disease is the result of the 

 presence of the microscopic organism Panhistophyton. M. Pasteur 

 has devised a method of extirpating the disease, which has proved to 

 be completely successful when properly carried out." 



-- 



MENTAL SCIENCE AND SOCIOLOGY. 



By HEEBEET SPENCEB. 



PROBABLY astonishment would make the reporters drop their 

 pencils, were any member of Parliament to enunciate a psycho- 

 logical principle as justifying his opposition to a proposed measure. 

 That some law of association of ideas, or some trait in emotional de- 

 velopment, should be deliberately set forth as a sufficient ground for 

 saying " ay " or " no " to a motion for second reading, would doubt- 

 less be too much for the gravity of legislators. And along with 

 laughter from many there would come from a few cries of " question : " 

 the entire irrelevancy to the matter in hand being conspicuous. It is 

 true that during debates the possible behavior of citizens under the 

 suggested arrangements is described. Evasions of this or that pro- 

 vision, difficulties in carrying it out, probabilities of resistance, con- 

 nivance, corruption, etc., are urged ; and these tacitly assert that the 

 mind of man has certain characters, and under the conditions named 

 is likely to act in certain ways. In other words, there is an implied 

 recognition of the truth that the effects of a law will depend on the 



