265 



have over them such influence, that the heads of "young people have turn- 

 ed white ^Jfcjae night before execution. The Revolution, which pro- 

 duced. inKiiBlance, the extremes of human suffering, furnished many 

 authentit^ftsXices of persons that grow hoary, in the space of a few days. 

 In this pBp]Jre hoariness, is the hair dried up, as in old people, when 

 it seems twf^B 01 ' want of moisture and its natural juices ? 



The folwHg fact seems to show, that they are the excretory organ 

 of some PflHRtej the retention of which might be of very injurious con- 

 sequence. H Bjhionk, who, every month, had his head shaved, accord- 

 ing to the^jMrof his order, quiting it at its destruction, went into the 

 army, and let his hair grow. After a few months, he was attacked with 

 excruciating head aches, which nothing relieved. At last some one ad- 

 vised him to resume his old habit, and to have his head frequently shav- 

 ed ; the head aches went off, and never returned. 



We know, says Grimaud*, that there are' nervous head aches, which 

 give way to frequent cropping the hair: when it is kept close cut, the 

 more active growth that takes place sets in motion stagnating juices. A 

 friend of Valsalva, as MorgagjJM' relates, dispelled a maniacal affection, 

 by having the head of the patient shaved; Casimir Medicus cured obsti- 

 nate gonorrhea, by the frequent shavings of the parts of generation. 



The hairs partake of the inalterability, the almost indestructibility of 

 the epidermis. Like it, they burn with a fizzing, and give out, in abun-. 

 dance, a fetid ammoniacal oil. These ashes, that remain from burning 

 them, contain much phosphate of limef. The horns of mammiferae, the 

 feathers of birds, give out the same smell in burning and yield the same 

 products as the hair on the head and other parts; which has led to the 

 saying that these last were a .sort of a horny substance drawn out like 

 wire. Acids, but especially alkalies, dissolve them : accordingly, all na- 

 tions that cut the beard, first soften it, by rubbing it with alkaline and 

 soapy solutions. 



Is the use of the hair to evacuate the superabundant nutritious matter? 

 The epoch of puberty and of the termination of growth, is that in which 

 it first springs, in many parts of the body, which were before without it. 

 They are, at the same time, the emunctory by which nature gets rid of the 

 phosphate of lime, which is the residue of the work o? nutrition. The 

 hairs of quadrupeds, whose urine abounds less in phosphoric salts than 

 that of man, seem especially to fulfil this destination. The hairs have 

 some analogy with the fat, which has not yet been ascertained. They are 

 often found accidentally developed in the fatty tumours known under the 

 name of steatomas. Finally, they have uses relative to the parts on which 

 they grow. 



CXXXV. The faculty of taking cognizance of tangible qualities, be- 

 longs to all parts of the cutaneous organ. We have only to apply a sub- 

 stance to any part of the surface of our body, to acquire the idea of its 

 temperature, of its dryness or moisture, of its weight, its consistence, and 

 even its particular figure. But no part is better fitted to acquire exact 

 notions, on all these properties, than the handy which has ever been con- 

 sidered as the especial organ of touch. The great number of bones 



* Second Memoir on Nutrition, p. 49. 



f -De Sedibiis et Cansis, Ernst. 8. No. 7. 



t See the Chapter in the APPEXDIX, on the chemical constitution of the textures, Sec. 



2 L 



