ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 251 



come into contact with a paper strip. They remain adherent to this 

 during the subsequent manipulation until ready for mounting. The 

 sections are made to adhere to the paper by means of a mixture of 

 equal parts of castor oil and collodion. This is not dissolved by xylol, 

 carbolxylol, alcohol, or water. It is dissolved by acetone, and an acetone 

 bath is used for the purpose of detacliing sections from paper. To 

 make sections stick to the slide, the latter is covered with a thin film of 

 photo-engraving glue. This is allowed to dry. The sections upon their 

 paper base are brought out of carbolxylol and placed upon a slide so 

 prepared, the sections being, of course, between paper and glass. The 

 carbolxylol has the effect of making the glue moist and sticky, so that 

 the sections are now adherent to slide on one side and to paper on the 

 other. Gentle pressure is applied, and in one or two minutes the whole 

 preparation is put in an acetone bath, which dissolves the collodion and 

 loosens the paper. This may then be carefully removed. 



The paper is kept in rolls, and a roll so placed that the sections 

 come from the knife on to the roll, the paper advancing as sections are 

 received. Celloidin sections pass from the microtome into a shallow 

 bath containing 80 p.c. alcohol ; from this they are placed upon the 

 paper strip, uniformly painted with a thin layer of castor oil collodion. 

 The paper with sections is blotted, and placed in carbolxylol. From 

 this bath the preparation is transferred to descending alcohols. The 

 alcohol bath is a shallow rectangular bath, one side of which is a hori- 

 zontally curved inclined plane. The preparations pass from the bath 

 on to the plane. 



JuiLLET, A. — Recherches anatomiques, embryologiques, liistologiques, et compara- 

 tives sur le Poumon des Oiseaux. 



Arch. Zool. Expir., xlix. (1912) pp. 207-371 (5 pis.). 

 See also this Journal, 1911, p. 822, where the technique is given. 



(4) Staining- and Injecting-. 



New Osmic Acid HsBmotoxylin Method.* — 0. Schultz makes some 

 remarks upon the use of osniic acid as a fixative, pointing out that the 

 reagent should not be kept in dark bottks ; that unless the portions of 

 tissue are v^ry small it should not be used in a concentration of less than 

 1 p.c, and that the time of action should be one or two days. He quotes 

 the method described by Flemmimr, in which the tissues are treated 

 with potassium bichromate, after the application of osmic acid. The 

 following method is recommended : — Tissues fixed for a day or two in 

 osmic acid are washed, and then placed in a • 5 per cent, solution of 

 hfematoxylin crystals in 70 p.c. alcohol. The material remains in the 

 stain for two days, the fluid being changed two or three times during the 

 first day. It is washed in 70 p.c. alcohol, until the brown stain ceases 

 to come away. After a day the tissues are transferred to 06 p.c. alcohol, 

 cedarwood-oil and paraffin. An alternative procedure consists in the 

 transference of the material from alcohol into a mixture of one part of 

 4 p.c. collodion and two parts 96 p.c. alcohol. After twenty-four hours 

 it is transferred to a mixture of equal parts of cedarwood-oil and chloro- 

 form, and then to paraffin. 



* 



Zeitschr. wiss. Mikrosk., xxvii. (1911) pp. 465-75. 



