SiGERSON — On Dextral Pre-eminence. 49 



case of an Italian gentleman, sick of yellow fever, who, at the begin- 

 ing of his illness, spoke English, in the middle of it French, and on 

 the day of his death Italian only. The languages fell away from him 

 apparently in the inverse order of their acquisition. The latest gained 

 was earliest lost. Instances of acquired accomplishments disappear- 

 ing, after illness, might be multiplied. 



!Now, to apply this pathological method. It has been my habit for 

 several years to test, with a hand-dynamometer, the grasp-strength of 

 patients when first seen, and at intervals afterwards. Originally, this, 

 system was adopted from the example of my late friend and instructor, 

 Dr. Ducheme (de Boulogne) in cases of paralysis ; but I generalised 

 the practice, and have, of course, excluded all cases from consideration 

 here, where loss of power might be due to any paralytic affection. 

 The patients in question, male and female, suffered from different 

 degrees of debility, arising from nervous depression, exhaustion, blood- 

 impoverishment, &c., general or sometimes special causes affecting the 

 constitution generally. 



Having noted down the figures indicating the relative grasp-powers, 

 dynamometrically tested, of right and left hands, it was obvious that 

 the right arm reduced more in strength than the left. As cases accu- 

 mulated, it became manifest that for a considerable series the rule is 

 general, and may be established as a pathological law, of some interest 

 and value. From thus simply testing the patient's power, it is possi- 

 ble to determine the existence of a discernible physical basis to his 

 complaint ; for it is plain that distinctions can be made— («) where the 

 grasp-power remains normal ; (h) where it is somewhat reduced, and 

 (c) where it is markedly diminished. 



Cases where there has been considerable diminution may be sepa- 

 rated into three groups or classes. In the first, or least-marked group, 

 I place those in which the right hand still retains a strength superior 

 to the left. On first testing, and if but once tested, it would be 

 sometimes impossible to say if the patient were in truth physically 

 depressed, though the lowness of the strength-standard would indi- 

 cate this unmistakably in certain cases. The subsequent augmentation 

 of strength, when ascertained by the dynamometer, suflSices to put the 

 matter beyond question. 



In the second class are placed those cases where the index points 

 to the same or to nearly the same standard for both hands. When 

 this happens, it may be taken as certain that we are in presence of an 

 abnormal condition : the right arm has suffered a loss much out of 

 proportion to that experienced by the left. Subsequent investigations 

 show that, as the patient recovers, the right regains its former predo- 

 minance in power. In the third class, the pendulum is seen to have 

 swung somewhat to the other side, for the grasp-power of the right 

 has even become, by some pounds, inferior to that of the left. Never- 

 theless, here also, just as in the other groups, as the general health 

 improves, the right hand steadily regains its old superiority in 

 strength. 



11. I. A. PIIOC, SEE. II., VOL. IV. — SCIENCE. H 



