and Laboratory Methods. 1817 



W 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



AGNES M. CLAYPOLE, Throop Polytechnic Institute. 



Separates of Papers and Books on Animal Biology should be sent for Review to Agnes M. Claypole, 



55 S. Marengo Avenue, Pasadena, Cal. 



Schneider, Q. Ueber den Ersatz von Glas ^^ an article on the subject by Dr. 

 durcb Gelatine. Zeitschr. f. wiss. Mikros. Pranter in the preceding number of the 

 u. f. mikros. Techn. 18: 288-200, 1002. '7 ■. t i- ■ ■,^■1 , • , . 



Zeitscn J. wtss. Mikros. (reviewed in 



Journal of Applied Microscopy, 5 : 4, 1902), it was stated that thin gelatine 

 plates used for cover-glasses actually possessed all the disadvantages known to 

 belong to the gelatine film. They are soluble in water and other fluids. They 

 bend and melt at a given temperature, as many photographers have learned. 

 These latter observers meet the problem by treating negatives after development 

 and fixation in a dilute formalin solution. This causes the gelatine films to lose 

 their easy solubility, their readiness to melt in, and also their capacity for stick 

 ing. The author asks whether such a. process may not be applied to the gelatine 

 cover-glass. For two years the author has used with good success the gelatine 

 capsules of the druggist for small glass tubes. Capsules of 25x10 mm. were 

 used, these little tubes were filled with 90 per cent, alcohol or a formalin solution, 

 and a label placed in the upper part of the capsule, which was put on as a cover. 

 A small number of such capsules are placed in a receptacle of 70 per cent, 

 alcohol or formalin. Only a few tubes should be used at a time or crushing will 

 result. More than one use of these tubes is impossible, since drying changes 

 their form and often tears them. Experience has shown that not all substances 

 can be equally well carried through in gelatine tubes, yet no general reasons 

 could be discovered for this fact. It would certainly be possible to prepare such 

 capsules when it is especially desired to have thin, transparent walls, and before 

 they are entirely dry to treat them with formalin. Moreover, fine openings may 

 be made in the cover to let out the air on closing the capsule and to admit freely 

 the liquid in which the capsule floats. In many cases it is more convenient to 

 keep the capsule afloat in a certain direction by the enclosed air bubble. Such 

 adaptations are impossible with the customary brittle glass tube. It still remains 

 to be seen whether the formol hardened gelatine is possible for slides, demonstra- 

 tion models, etc. a. m. c. 



Harris, H. F. A New Method of Staining Elastic The author accidentally discovered that 



Tissue. Zeitschr. f. wiss. Mikros. u. f. Mik- hematein solutions, prepared in a certain 

 ros. Techn. 18: 200-201, 1002. , 1 1 1 rr -^ /■ 



^ ^ way, have a remarkable affinity for 



elastin, giving a clear differentiation of this substance. So satisfactory are the 

 results that the stain was used to the exclusion of the usual Weigert method. 

 The stain is made as follows : Hematoxylin 0.2 g., aluminium chloride 0.1 g., 

 50 per cent, alcohol 100 c. c. Dissolve the hematoxylin and aluminium chloride 



