86o 



POPULAR SCIENCE MONTHLY. 



dren : (1) In cases of ill health from tuber- 

 culosis, etc., anccmia being almost always a 

 prominent symptom ; and (2) in healthy 

 children, the habit being formed in infancy 

 and disappearing spontaneously when the 

 children are about three years old. Dr. 

 Thomson regards the habit in this latter 

 class as analogous to thumb-sucking, perpet- 

 ual rocking to and fro, or constant rolling in 

 bed, in which some children find delight and 

 which they lose when they pass out of in- 

 fancy. The materials selected are chiefly 

 wall plaster and cinders. One child varies 

 the latter by pushing the hearth brush into 

 the ashes and then licking the dust oif as a 

 great delicacy. The habit, as is well known, 

 is common among imbeciles and idiots ; but 

 Dr. Thomson's cases were free from mental 

 disorder. Dirt-eating may lead to serious 

 consequences when the material eaten con- 

 tains harmful matter. The native Egyp- 

 tians, who, observing the marvelous fertiliz- 

 ing power of Nile mud, imagine it must be 

 equally nutritious for men, habitually eat it, 

 with the result of infecting themselves with 

 the ova of anchylostoma, bilharzia, and 

 other parasites. 



Piano Toneli. When a certain point of 

 perfection has been attained in piano- play- 

 ing it becomes very hard to distinguish in- 

 equality of touch ; yet, owing to the varying 

 strength of the fingers, it is only with much 

 practice that perfect equality is possible. 

 An account of an apparatus for graphically 

 registering these inequalities is given in a 

 recent issue of Nature. The instrument was 

 devised and used for experimental work by 

 MM. Binet and Courtier. It is said to be 

 simple in construction and vei'y accurate. 

 The advantages claimed for the instrument 

 are threefold : (1) It is found that the vol- 

 untary movements of the pianist can be ob- 

 served without putting him to any restraint 

 or embarrassment, for the resistance of the 

 keys is not affected nor is the exterior of the 

 piano altered ; (2) for teaching purposes the 

 device has been found of great use ; the rec- 

 ord made on a roll of paper shows the faults 

 so precisely that, although they arc scarcely 

 perceptible to the ear, there is no denying 

 their existence ; (3) written music can not 

 show every slight change in time the com- 

 poser might desire, but by applying the 



graphical method this diflSculty is elimi- 

 nated and the time will be reproduced with 

 the smallest details. 



The Cigar-Case Bearer. A new fruit- 

 tree pest has recently appeared in New York 

 State, and is described in a bulletin from the 

 Cornell Experiment Station. It is called the 

 cigar-case bearer. Owing to its small size 

 and peculiar habits, the insect in any stage 

 will be rarely noticed by a fruit-grower, and 

 yet the second one of the curious suits or 

 cases which the little caterpillar wears is 

 conspicuous enough to reveal its presence to 

 the casual observer. The first suit is manu- 

 factured in the fall, to be worn all winter; 

 but about the 15th of May the half-grown 

 caterpillar finds this too small, and proceeds 

 to make a summer suit which resembles a 

 miniature cigar in shape and color. The 

 first indication of the insect's presence oc- 

 curs on the swelling buds of apple, pear, or 

 plum trees. The work on the expanded 

 foliage is seen in skeletonized dead areas, 

 which have near their centers a clean-cut 

 round hole through one skin, usually on the 

 under side of the leaf. The caterpillars also 

 often attack the growing fruit. It is only 

 possible to fight the insect successfully in 

 the caterpillar stage, and even then it re- 

 quires very thorough work to destroy it. 



A Contemplated Antarctic Expedition. 



A committee has been formed in London to 

 promote a mercantile and scientific antarc- 

 tic expedition, and has already published its 

 plan of operations. The scientific contin- 

 gent, which will be accompanied by Mr. C. E. 

 Borgrevink, will consist of twelve English- 

 men trained in science, equipped with the 

 necessary huts, dogs, sledges, etc., and will 

 be left at Cape Adare, with the expectation 

 of spending one year in South Victoria Land. 

 The investigations will include the work of a 

 land party toward the south magnetic pole, 

 there to make magnetic observations ; a sur- 

 vey of the coast line of the open bay, with 

 exploration and soundings of fiords and bays ; 

 the making of zoological, botanical, miner- 

 alogical, and geological collections; dredg- 

 ing ; and barometrical, thermometrical, mete- 

 orological, pendulum, air-current, and water- 

 current observations. While the scientific 

 men are thus exploring the land, the vessels 



