TRANSACTIONS OF SECTION I. 815 



The following Papers were read : — 



2. On a Modification of Golgi's Methods. By Oliver S. Strong, of 

 Columbia College, New York. 



Golgi's methocls may be divided into two principal heads : (1) The sublimate 

 method, consistinp; essentially of hardening in bichromate of potash followed by 

 immersion in bichloride of mercury. This method need not be further noted here. 



(2) The silver methods, consisting of (a) the long, or slow, method, consisting 

 of hardening for about twenty to thirty days in potassium bichromate followed by 

 immersion in a solution of silver nitrate. (6) The rapid method, where the har- 

 dening is done in a mixture of bichromate and osmic acid. This is the method, 

 slightly modified, which is so extensively used, and is the method used by 

 E-amon y Cajal. (c) What may be designated the mixed method, or combined 

 method, and consists in hardening first for a few days or a week or so in potassium 

 bichromate, then a day or two in the osmium-bichromate mixture, and finally the 

 immersion in the silver bath. 



The rapid method is the best yet discovered for work on the peripheral ter- 

 minations of nerves and for the embryonic central nervous system. For adult 

 brains it is not so well adapted owing to the poor penetration of the osmic acid, 

 and consequent liability to overharden the periphery while the central portions of 

 even small pieces remain untouched. Moreover, adult brains are not well adapted 

 for the study of the nervous or axis cylinder prolongations of the cells, owinc 

 probably to their sheath, so that on such material study by these methods would 

 be chiefly directed to the cell bodies and their protoplasmic expansions. For 

 such purposes the long Golgi method is eminently adapted. 



While the long Golgi method avoids the disadvantages, including the expense 

 — no small consideration where such quantities are used — of osmic acid, it has the 

 disadvantage of requiring about a month, besides the uncertainty common to all 

 these methods. 



In order to reduce this period of time, and yet to avoid the use of osmic acid, the 

 new method here proposed for the study of adult brains is the use of bichromate of 

 lithium instead of the bichromate of potassium, with the same percentages. I have 

 found that tissues (small pieces) placed in the former reach the favourable stao-e of 

 hardening for the silver impregnation in the course of one to two days, instead of 

 twenty to thirty days. It passes through this favourable period quite rapidly, but 

 the whole process is reduced to such a short time that it is rendered much less 

 tedious. The pictures yielded by this process, judging from the few made thus 

 far, are certainly fully equal to those prepared by the other methods. 



The subsequent treatment is as in the other methods, i.e., the piece of tissue 

 is rinsed in strong alcohol, cut free hand or gummed on a block without any 

 imbedding, and cut with a microtome. The sections are washed in several 

 changes of strong alcohol, cleared in oleum origanum Cretici, washed briefly in 

 xylol, and mounted in dammar or Canada balsam, thinned with xylol, without a 

 cover slip. 



It would be interesting to ascertain how well adapted this new hardening 

 reagent would be for preparing the central nervous sj'stem for other methods of 

 staining, e.g., the Weigert method. 



3. On an Attempt to supply Motor Power to the Muscles of the Larynx from 

 a New Source. By Veterinary-Captain F. Smith, F.R.C.V.S., F.I.C., 

 Army Veterinary Department, Aldershot. 



The subject used in these observations was the horse, the inquiry having in 

 view the possible relief of the respiratory distress so common in this animal as the 

 result of laryngeal paralysis. 



The new source of nerve supply was sought for in the spinal accessory. The 



