The reaction can be tested in fresh stools, by means of previously moistened strips of litmus paper.
The ash-content can be approximately estimated by the ignition on a platinum beaker of small particles of the feces (Heubner).
The ehemieal examination of the stools, in regard to which the odor gives much essential information (Scher), is performed clinically in the following way. The stool is tested for lactic acid,* by extracting with ether, filtering, evaporating the ether, dissolving the residue in water, and adding one or two drops of a solution of ferric chloride in carbolic acid (10 c.e. 1 per cent. carbolic acid plus 1 to :3 drops of ferric chloride). A yellow or yellowish green color appears. The test for acetic and suecinic acid, which are further fermentation products of the sugar in the food, is made in the following way. The stool is extracted with water, filtered, and then heated with a couple of drops of alcohol and sulphuric acid, upon which a clear odor of vinegar appears.
By means of the methods briefly sketched above, in connection with the inspection of the discharges, the appearances of which under pathologic conditions will be considered in speaking of the different disease types, sufficient material is found for clinical requirement, and for diagnosing the nature of the disturbance as well as the eventual result of therapeutics.
Just as important is the examination of the urine, for the collection of which can be used with boys the urine collector constructed by Raudnitz, with girls a metal catheter. Beside the usual albumin and sugar tests, the test for indican must not lie neglected. According to Combe its amount is a measure of the degree of intestinal putrefac tion, a view of the accuracy of which Leslie and Merklen doubt on the basis of their own researches. The testing of the alimentary glyeosuria, and of the elimination of methylene blue has hitherto given no results of practical value (Lense-Merklen).
Obviously in addition to the chemical examination, there must be a thorough microscopic search of the sedimented or centrifugal ized urine, and finally also the taking of cultures.
The test of the toxicity of the urine proposed by Bouchard has proved worthless, as Brieger has been able to show, that if the urine is simply diluted until isotonic with the blood serum of the individual, its toxic action is entirely removed iCombe).
Also the results of cryoscopy of the urine (Nobecourt, Lesne Merklen), and of the testing of the velocity of its flow with the stal agmometer (Arnann) have made but little progress, and are superfluous for our purpose.
The examination. of the blood can be made from cover-glass prepa rations stained in the usual way, with counting of the different forms of leueocytes by means of a movable stage. This informs us as to the existence of a leucoeytosis and as to its character. However, the reports respecting this in the literature (Japha, Mason-Knox, Wacfield, Zahorsky), sound rather contradictory, so that the prognostic value of such findings must be taken with caution.
The counting of the leueocytes by means of the Thom-Zeiss apparatus permits an exact estimation of their increase, and of the influence of digestion and the effect of nourishment with cow's milk upon leucocytosis, etc. (Moro).
Also the estimation of the specific gravity of the blood by means of the pyknometric method is, according to Schlesinger, of prognostic value.
The usual method of examining the blood of infants bacterio logically, by pricking with a needle and inoculating on various culture media (Czerny-Moser, A. Baginsky, O. Heubner, Escherich, Pierracini, and Nencioni, et al.), has shown such divergent results, and is beset by so many sourees of error, that it had much better not be employed. The only reliable method is the withdrawal of a greater quantity of blood (at least 1 c.c.) by means of a syringe from a vein of the fore arm. This proceeding can only occasionally be decided on, because at times the withdrawal of so much blood front a poorly nourished infant can not be undertaken without hesitation, and because at other times it is impossible on account of the small size of the veins and the peripheral anremia of the body. Lesne in one ease has had recourse to puncture of the longitudinal sinus through the greater fontanelle, a procedure which should not find many imitators.
The agglutination test, a proceeding easily carried out clinically, has brought about no practically useful results in respect to the bac terium coil, but has been instrumental in shattering the supposed position of this organism in the pathogenesis of gastro-enteric affections (Nobecourt, Escherich, Pfaundler, Lesage, Templieu, et al.). It appears to give more constant and more clinically valuable results with the different types of dysentery bacilli (Flexner-Holt, Jellle).
There remains lumbar puncture to be mentioned here, which can be employed in cases where nervous symptoms accompany diseases of nutrition. It is used as a diagnostic procedure in differentiating be tween the functional nature of such symptoms, and tneningeal or cerebral complications (Nobecourt).