680 SUMMARY OF OURUENT RliSEARCHES RELATING TO 



Collin's Automatic Cannula-holder.— Ou tlio otlicv haiul, Prof. H. 

 Fol * prefers a pressure arraiigemcut, on tlio ground that with all forms 

 of syringe the leather dries up when it has not been used for some 

 time, witii the result that when the syringe is wanted it is not in a 

 serviceable con^lition. 



Whatever form of pressure-apparatus is used, it is very convenient, he 

 poiuts out, to have a cannula-holder with an automatic closing arrange- 

 ment, such as that of MM. Collin shown in fig. 11 G. 



Fig. 116. 



The holder is hollow, and is connected with the tube from tho 

 pressure apparatus. Having been filled with the fluid, and some having 

 been allowed to run out of the cannula, the cock is closed and the cannuhi 

 is placed in the vessel to be injected, the holder being held in the hand 

 like a pen. By pressing the lever the flow of the fluid can be regulated 

 as desired. Prof. Fol says, " Whoever has worked with such an instru- 

 ment will hardly again use the old syringe, especially where difficult 

 injections of invertebrate animals have to bo performed." 



(5) Mounting:, including Slides, Preservative Fluids, &c. 



Half-clearing method of preparing Nerve Sections.t— Dr. Byrom 

 Bramwell lays the section previously stained with carmine on a slide, 

 and then pours on methylated spirit ; the spirit is then mopped up, 

 and a small quantity of oil of cloves poured on. While the prepara- 

 tion is still cloudy the oil of cloves is drained off quickly, and having 

 been replaced by Canada balsam, the cover-glass is put on. The 

 results attained, although in some cases extremely good, are eminently 

 uncertain on the whole, the preparations being spotty, irregularly or 

 too much cleared up. 



Adaptation of Kaiser's gelatin for arranging microscopic prepara- 

 tions in rows4 — Signer A. Poli commends to the notice of botanists, 

 especially for the preservation of algae, the mixture of gelatin and 

 glycerin known as Kaiser's glycerinated gelatin, as first proposed by 

 Nordstedt, and recommended in Strasburger's ' Botanisches Practicum.' 

 He finds it especially convenient when it is desired to arrange a number 

 of minute objects in rows under the same cover-glass. A fine streak of 

 the fused gelatin, which melts at 45^ or even lower, is first placed on the 



* Fol's Lelubuch, p. 24 and pp. 25-6 (1 lig.)- 



t Edinburgh Med. Journ., Oct. 1886. J Malpigbia, ii. (1888) pp. 107-9. 



