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 PKOGEESS OF MICROSCOPICAL SCIENCE. 



Detection of Consumption with the Microscope. — In the ' Boston 

 Joiirnal of Chemistry ' for December, Dr. J. G. Eichardson, micro- 

 scopist to the Pennsylvania Hospital, has an important note in 

 which he fully bears out the views of our London physician, Dr. 

 Fenwick. He says that according to his o^mi observations he has 

 found it useful to direct the patient to use no tobacco, to rinse out his 

 mouth after meals before expectorating into his cup, and to avoid 

 mixing the sputum of any other person with his own ; in general, he 

 has boiled about an ounce of the tenacious sputa with their own bulk 

 of liquor sodae in a four-ounce porcelain capsule or evaporating dish, 

 and, when liquefied, poured the fluid into a conical vessel containing 

 two or three times its bulk of water, quite slowly, to avoid cracking 

 the glass. Although it is by no means easy to describe the appearance 

 of lung tissue without the aid of drawings, perhaps most of his readers 

 may be able to detect its presence by the following characters, espe- 

 cially if they will take the trouble to mince up a piece of healthy or 

 tuberculous lung, and examine it as above directed after boiling in 

 caustic soda. Under a power of 200 diameters, the fragments of the 

 pulmonary air-vesicles appear to be composed of curved and curled 

 fibres, each about the diameter of a horse-hair, and of a shining bluish- 

 white colour, resembling that of the fascia lata in the thigh ; their 

 most characteristic peculiarity (observed in some part of a majority of 

 the specimens) is the arrangement of two or more fibres in the shape 

 of a ca])ital Y, with a third filament crossing from the extremity of 

 one arm of the letter to the other, thus presenting the appearance of 

 being the meeting point of the walls of three air-cells, which, when 

 enough of their outline remains, are each seen to have been from ah 

 inch to an inch and a half across. The novice must be on his guard 

 against mistaking for lung tissue, first, small fragments of flax fibres, 

 which, when partly split, often assume the Y shape, but without the 

 cross-bar ; second, masses of Leptothrix buccalis from the mouth, whose 

 component filaments do not appear coarser than the finest hair from 

 an infant's head ; third, portions of vegetable structures, whose cells 

 are generally smaller, while their fibres are larger and less sharply 

 curled ; and, fourth, wrinkles in the cell walls of boiled starch cor- 

 puscles, which may be detected by very close scrutiny, or by bringing 

 the remainder of the cell into view, by means of tincture of iodine, 

 or aniline solution. In addition to these suggestions, the following 

 remarks, quoted from his ' Hand-book of Medical Microscopy,' p. 

 210, may help some observers to escape mortifying blunders of this 

 nature : — " After much careful investigation of various specimens of 

 sputum from both hospital patients and cases in private practice, for 

 the purpose of detecting some characteristics of the lung tissue by 

 which it coidd be promptly and certainly recognized, it occurred to 

 me that the fibres of the air-vesicles, being clastic, must break, like a 

 thread of india-rubber, with a squai'c transverse fracture, wliile the 



