Dec. 1st, 1887.] 



SCIENTIFIC NEWS. 



half-a-crown a grain, that is, ^"60 an ounce. Cocaine has a 

 bitterish taste, and crystalises in prisms. This bitter taste 

 is due to the presence of theine; and it is to this theiue 

 that the remarlcable properties of the drug are partly to be 

 ascribed. In many particulars, and in its physiological 

 action upon the system, the cocaine was found to resemble 

 atropine, the alkaloid of deadly nightshade. 



Cocaine unites with acid to form salts, the best known 

 being the hj'drochlorate, though the nitrate is more used. The 

 former preparation consists of small white needle-shaped 

 crystals, with a peculiar characteristic odour, and is soluble 

 in water in the proportion of one to four. When Niemann first 

 extracted the drug from the coca leaves he was surprised 

 to find that, on applying it to the tongue, he experienced 

 no taste, and the tongue was destitute of feeling. Two 

 years afterwards, in 1S62, Schroft" found that a dose of 

 three-fourths of a grain given to a rabbit very materially 

 disturbed the pulse and respiration. In 1S74 Dr. Bennett 

 showed that cocaine exerted its influencechiefiyon thesensory 

 nerves, and was a powerful anaesthetic. Four years after- 

 wards Dr. Ott published a paper showing that it dilated the 

 pupil of the eye just as in the case of an excess of 

 chewing the leaves. The very high price of the drug, 

 however, prevented for a time any continued experiments 

 upon the lower animals, and it was not till 1884 that the 

 beneficent effects of the wonderful pain-reliever were pub- 

 licly demonstrated. 



At the Oculists' Congress, held in Heidelberg three years 

 ago. Dr. Keller, of Vienna, first publicly showed the action 

 of cocaine when applied to the eye. He had long been 

 aware of the anresthetic power of the drug on the larynx ; 

 but at the Congress he publicly introduced two drops of a 

 two per cent, solution into the eye of a patient, and in two 

 minutes pointed out that the sensitiveness of the surface had 

 been aflected. Two drops of a four per cent, solution 

 completed the deprivation of all feeling in the eye. A probe 

 was pressed upon the front hard, transparent covering of 

 the eye until the surface was indented ; the lids were 

 stretched to their utmost, and the globe was moved about 

 in various directions by means of forceps ; but the patient 

 was like one under mesmerism, suffering neither pain nor 

 inconvenience. 



A knowledge of Dr. Roller's famous experiments and 

 remarkable discovery spread rapidly, and in a few days 

 hundreds of workers were in the field, keen to make im- 

 provements on its application, and anxious to have their 

 names connected with a discovery which seemed to be about 

 as beneficial to suft'ering humanity as chloroform had proved 

 itself. Cocaine was dropped into the eye, rubbed into the 

 skin, applied to the larynx, and even injected. An unwonted 

 excitement possessed the medical world, eager to win 

 Simpsonian laurels. Though many well-meaning but 

 over-enthusiastic writers on the subject, in detailing the 

 results of their own experiments, have exaggerated the 

 beneficial effects of the drug on its application to the diffe- 

 rent parts of the frame, there is no doubt it is of 

 inestimable value for the prevention of suft'ering in opera- 

 tions on the eye. Professor Knapp, of the University of 

 New York, bravely experimented on himself and on members 

 of his own family. He found that the pupil of the eye 

 begins to dilate in from ten to twenty minutes with a four 

 per cent, solution of cocaine, slowly increases in size, and 

 attains its maximum in three-quarters of an hour, and then 

 gradually diminishes. The feeling is deadened for three 

 minutes ; sensibility then begins to appear, until in half an 

 hour sensitiveness is restored. An experienced oculist. 

 Dr. Argyle Robertson, of Edinburgh, has been very suc- 

 cessful in the use of cocaine. When operating for cataract 

 he deadens the nerves of the eye by repeated applications 



of a weak solution for half an hour before the operation, 

 and the patient, though aware of a slight pricking when 

 the instruments are inserted to steady the eye, is astonished 

 to be assured that what was considered the preliminaries 

 was really the operation. 



Cocaine has now been shown to be a powerful anresthetic. 

 By it, wens, or skin tumours, are successfully removed with- 

 out pain. Operations on the larynx and the ear have been 

 painlessly performed. In certain forms of neuralgia, a ten 

 per cent, solution in oil of cloves rubbed into the affected 

 part affords almost immediate relief. Taken internally, small 

 doses stimulate nerve centres, lessen fatigue, diminish the 

 saliva and perspiration, and quicken the rate of the pulse ; 

 but large doses paralyse the nerves, produce fulness of the 

 head, deafness, and stupidity, raise the temperature of the 

 body and lower the pulse. The best physicians consider 

 cocaine far before ether or morphia for local anaesthesia. It 

 has been found very beneficial in cases of hay fever, tab- 

 loids of cocaine being successful in stopping the annoying 

 accompaniment of this disease when all else failed. For 

 ordinary relaxed throats, occasioned by exposure to the ex 

 treme frosts of a hard winter, cocaine lozenges have been 

 found more advantageous than the old krameria lozenges. 

 Of course, by rash employment in inexperienced hands, 

 it has acted like a poison on the system of the patient, 

 which has made the pessimists of the profession sneer 

 down its beneficial effects ; but caution as to the quantity 

 used for the age and constitution of the patient will prevent 

 any serious results. And, though still in its infancy, cocaine 

 has been found by the best medical practitioners, even in 

 country districts, to be the most important discovery since 

 that of chloroform for the alleviation of suffering. 



CLINICAL THERMOMETERS. 



THE accompanying illustrations refer to a clinical ther- 

 mometer made by M. Leon Bloch, of Paris. Its 

 outward shape is very similar to the ordinary clinical 

 thermometers, and has the usual narrow passage imme- 

 diately above the mercurial reservoir (as shown in Fig. i). 

 This permits the mercury to pass when it is expanding, but 

 causes the column to break when the mercury contracts, 

 and thus records the maximum temperature attained. The 

 mercurial reservoir in the thermometers usually employed 

 is made of very thin glass, and expands a little with an in- 



Perspective View of Thermometer. 



crease of temperature. There is therefore a tendency to 

 check the rise of the mercurial column, so that a lower 

 temperature than that actually existing will be indicated. 

 Besides this, some minutes must elapse before the maximum 



T>llllb I I Ibiii^i 



Sectional View of Bulb. 



can be taken, owing to the comparaiively large quantity of 

 mercury to be affected. In M. Bloch's thermometer, however, 

 the bulb is made longer than usual and is provided with a 

 second internal tube (as shown in section in Fig. 2). An 



