1888.] MICKOSCOPICAL JOUKNAL. 95 



water acidulated with a few drops of acetic or hydrochloric acid ; then trans- 

 fer them for about one minute to a strong aqueous solution of iodine green ; 

 wash them in rectified spirit, and mount in the usual manner. 



CHLORIDE OF GOLD, ROSEIN, AND IODINE GREEN. 



This is a most beautiful combination for preparations containing growing 

 bone ; but it is one which requires great care, and a certain degree of skill in 

 the use of staining reagents to employ satisfactorily. The staining is well 

 shown in the tail of a young rat or mouse. 



Cut oft' the tail of an etherised rat or mouse, and divide it into pieces an 

 inch long; place them in a i% solution of gold chloride for one hour, and then 

 transfer them to a mixture composed of 40 cc. and to cc. formic acid. Keep 

 the bottle in the dark. In from eighteen to twenty-four hours the gold will 

 be completely reduced, and the lime-salts removed from the bone. Harden 

 the pieces of tail in strong rectified spirit for three weeks, changing the spirit 

 at the end of the first hour, the first, third, and seventh days. Make sections 

 with the freezing microtome, and stain them, first with an aqueous solution 

 of iodine green, and then with an alcoholic solution of rosein. Mount in 

 Canada balsam. 



The gold will be found principally on the skin and tendon cells, the anilines 

 on the underlying tissues. 



Very many combinations, besides those which I have described, will be 

 discovered by an experimenter in this art, but it is doubtful whether any dis- 

 coveries in this direction will bring to light new facts connected with his- 

 tology ; still, improvements on present methods might be hit upon, and 

 would be welcomed by microtomists. 



Beginnners in staining should, as in every other art, follow out directions 

 strictly; they will then learn the reason, the c/ienihtry of each operation, 

 and, after this, will be able to alter or modify processes to suit sj^ecial cases, 

 or to extend the application of those processes to fresh branches of work. 



EDITORIAL. 



We desire to call particular attention to the method for imbedding vegetable 

 tissues in paraffin, described in another portion of this Journal from the 

 original paper in the Botanical Gazette. Upon perusing the original, we 

 were at once convinced that Dr. Moll had found a valuable method. We 

 have since had the good fortune to receive from Prof. C. R. Barnes, of Madi- 

 son, Wisconsin, a slide with several sections prepared after the plan suggested 

 by Moll. If we might venture any suggestion of a possible improvement upon 

 the method, it would be that the staining should precede the cutting of the 

 sections and not follow it. This would present no difficulty so far as we can 

 see. The vital point in the discovery is in the mode of preserving the tissues 

 for cutting. Subsequent to that the tissues can doubtless be subjected to the 

 same treatment as animal tissues. The valvie of the process scarcely calls for 

 comment with those who understand what serial section-cutting is to zoology. 



o 



Science in Australasia. — We only think of our own country as the one 

 where wonderful progress has taken place. The people of San Francisco, 

 Denver, Chicago, St. Paul and other cities of beauty and progress are proud 

 to compare the present with a couple of decades ago — and with reason. But 

 the antipodes are also doing the same. In Australia, New Zealand and other 

 outposts of British colonization progress has been the rule. This is forcibly 

 presented in the English journal of scientific news — Mature. We have no 

 such American journal to which we can turn to know what scientists are do- 



