500 RECORD OF CURRENT RESEARCHES RELATING TO 



be picked up in many places and powdered in the field), a small bottle 

 of common balsam, made very Lard, a .few corks, some pieces of 

 broken window glass, a few thin covers, or, if they are omitted, pick 

 lip mica from some of the rocks, and use thin sheets of that instead 

 (except in some cases where it would interfere with the use of polarized 

 light upon some rocks) ; in addition to these, a small piece of iron 

 plate for grinding upon completes the outfit, all of which will fit into 

 the tin box. 



The processes are simply as follows : Break ofi" very thin flakes 

 from the rock to be examined, a piece one-eighth of an inch in diameter 

 is large enough ; take the small piece of smooth flat iron (a stove lid 

 will do), place a little flour emery with water upon it, then, with the 

 flake of rock upon the iron j^late, press upon the section with a cork 

 for a holder, and rub one side by grinding with the emery until that 

 side has been made smooth and flat ; take a small piece of the window; 

 glass, and by melting some of the balsam cement the smooth side of 

 the section to the glass. Now take the glass in hand, aud with the 

 other side of the section down to the jplate, with emery, grind as before, 

 until newspaper print can be clearly seen through it. This will answer 

 well for ordinary examination, but with care many rocks may be 

 polished finer and thinner than this. Now take one of the cover- 

 glasses or laminfE of mica, and with the melted balsam place upon the 

 uncovered side, and the section is ready for microscopic examination. 

 All of this can be done in ten minutes anywhere in the field. 



Test for Amyloid Substances.* — Safranine, one of the red aniline 

 dyes, is recommended for the detection of amyloid matter. It is 

 soluble in water and alcohol. Sections immersed in a watery solution 

 of safranine (one or two grains to the ounce), are stained rapidly, the 

 amyloid substance showing a beautiful orange colour, while the rest 

 of the section is of a rose colour. Epithelial cells are more deeply 

 tinted than connective tissue. Thick tissues colour well ; tissues 

 which have been hardened in alcohol stain well ; but not those which 

 have hardened in chromic acid or the bichromates. Acetic acid 

 destroys the value of the test, the entire sjDecimen being stained of a 

 uniform rose tint in the presence of this acid. 



Pierocarmine Staining in Inflammation-Studies.f — Professor 

 Neumann in describing his method states that the mixture adopted by 

 Schweigger-Seidel of one part muriatic acid and 200 parts glycerine 

 is very useful ; instead of this, one or two drojis of acid may be added 

 to ten cubic centimetres of glycerine, and the moment carefully 

 watched for, under the Microscope, at which the solution has comjileted 

 its action ; this method may be adopted for specimens preserved in 

 alcohol as well as for those that have been in Miiller's fluid or 

 in chromic acid. This solution is applied after the sections have in 

 Eanvier's solution taken on a more or less distinct orange-red color- 

 ation. 



The author enters into a detailed account of the value of this 



* 'Med. Herald' a-ouisville, U.S.A.), i. (1880) p. 523. 

 t 'Arch. Mikr. Ariat.,' xviii. (1880) p. 130. 



