CORRESP ONDENCE. 



8+5 



CORRESPONDENCE. 



MEDIAEVAL JEWISH SCIENCE. 

 Editor Popular Science Monthly : 



SIR : President White, in " New Battles 

 of Science," shows up the reactionary 

 influence of the Christian writers in the 

 middle ages on the knowledge of Nature, 

 beginning with Cosmas Indicopleustes and 

 ending with Albertus Magnus their denial 

 of the earth's spherical shape, their bring- 

 ing rain from beyond the firmament, etc., 

 all on the strength of Scripture. Now, 1 am 

 proud to say that my brethren, the Jewish 

 scholars of the middle ages, did nothing 

 to push science backward, but took it up 

 cheerfully where the Greeks had left it. 

 The two leading philosophic works of mid- 

 dle-age Judaism, both written in Southern 

 Spain, and in the Arabic tongue, are the 

 " Moreh Nebochim " ("Teacher of the Per- 

 plexed ") of Maimonides, strongly rational- 

 ising, and therefore ill received by many, 

 and the " Cozari " (feigned conversations 

 with a " Chazar," khan, converted to Juda- 

 ism), of the great Jewish hymn-writer, Je- 

 huda llallevi, published in a.d. 1140, thor- 

 oughly orthodox. He rejects the meta- 

 physics of Aristotle and of Epicurus, but 

 recognizes what Greece has achieved in 

 physics. Speaking of the Sabbath (Part II, 

 20), he assumes for the three Eastern 

 Continents an extent of twelve hours, or 

 180 in longitude, and a like extent for the 

 ocean, which Columbus had not yet parted 

 in two ; he puts Jerusalem midway between 

 Tsin (China) and westernmost Africa, and 

 tells us that when the Sabbath begins there 

 on Friday evening at six it is midnight in 

 China, and still Friday noon in the extreme 

 West. Not exact, according to our lights, 

 but up to all the light of his own time. 

 Elsewhere lie boasts of the astronomic 

 learning of Rabbi Samuel, an early Tal- 

 mudic writer, and shows that he and his 

 friends studied the stars only for the pur- 

 poses of the calendar, new moons, and 

 equinoxes, not with any view to horoscopes. 

 He states with pride that, in the rules for 

 killing and examining beasts for food, the 

 Talmud shows more knowledge of the anat- 

 omy of the lungs than can be found in Ga- 

 len. He also claims that long experience 

 had proved the Jewish measurement of the 

 synodic month and tropical year to be more 

 correct than the numbers given by Ptolemy. 

 He finds no occasion to speak of the origins 

 of rains and thunder-storms ; but the ab- 

 surd notion that rain comes from beyond 

 the firmament could never occur to any of 



the Old Testament writers, who lived on the 

 narrow strip between the Great Sea and the 

 Syrian Desert, and got their rain with the 

 west wind and their dry heat with the 

 dreaded east wind (kadim), nor to any one 

 who read their books in the Hebrew text. 

 The "Cozari" proves that in the darkest 

 ages our race kept its mind unclouded. 



The opinion that thunder-storms are the 

 work of the devil or of evil spirits could not 

 grow up among a people who were taught 

 from their childhood to greet lightnings or 

 falling-stars with the benediction, " Blessed 

 be thou, Lord, who doth the work of 

 creation ! " and to welcome thunder with the 

 kindred formula, " Blessed be thou, Lord, 

 of whose strength and of whose might the 

 world is full ! " Respectfully, 



Lewis N. Dembitz. 

 Louisville, Kentucky, July 11, 1S87. 



HATS AND BALDNESS. 

 Editor Popular Science Monthly : 



Sir: A few months ago you published 

 in the pages of the " Monthly " an article on 

 hats as a cause of baldness, which has been 

 extensively quoted and has attracted much 

 attention. I have delayed writing to you 

 on the subject until I had leisure to look 

 up an article written by my father, the late 

 Dr. Austin Flint, nearly thirty-five years 

 ago. I send an extract from this article 

 which appeared as an editorial in the " Buf- 

 falo Medical Journal," March, 1853, No. 10, 

 page 651, and was entitled " Hats and Bald- 

 ness ":"... The most characteristic trait 

 of the hat is the tightness with which it en- 

 circles the head. Herein consists, in our 

 opinion, its agency in the loss of hair. The 

 stove-pipe hat must needs encircle the head 

 tightly, in order to be secure in its position 

 in spite of wind and other disturbing forces. 

 To appreciate the degree of compression, 

 one has only to note the indentation on the 

 forehead after a tightly-fitting hat has been 

 worn for some time. Everybody knows 

 how commonly this is to be observed. The 

 head is, in fact, pretty firmly ligated while 

 the hat is worn. Now, what must be the 

 effect of this on the circulation ? Plainly, 

 the effect is to interrupt the circulation in 

 the scalp above the circle on which the com- 

 pression is made. It is precisely like tying 

 a cord around the head, sufficiently to di- 

 minish, if not stop, for the time, the flow of 

 blood through the temporal and other ar- 



