156 REPOllT ON NATIONAL MUSEUM. 



The chemist makes the following statements upon the present condi- 

 tion of the laboratory : 



The present condition of the chemical laboratory is, with very few exceptions, most 

 promising. In the balance-room we have three No. 7 analytical balances, one large 

 analytical balance to carry one kilogramme, one assay button balance, one small so- 

 called prescription scale, one pulp scale for assay charges, and one Jolly's balance for 

 specific gravity determinations. 



Ample facilities for the preparation of samples for analysis are provided, the labo- 

 ratory being provided with a small Blake crusher for reducing samples to small frag- 

 ments, a ' ' buck plate " for assay samples, and a number of valuable agate mortars for 

 preparing samples of silicates, rocks, &c., where iron cannot be used. 



The facilities for assaying are good, there being three furnaces for that purpose, one 

 forcrucibles, andtwo for scarification and cupellation. The stock of glassware is good, 

 as also the porcelain. The main feature of the laboratory, however, is the fine stock 

 of platinum ware in the form of dishes and crucibles, the laboratory possessing 19 

 platinum dishes holding from 50 cubic centimeters to nearly half a liter, and 25 plat- 

 inum crucibles. In addition to the 2,070 grammes spoken of, the Institution has pur- 

 chased at diiferent times about 700 grammes of platinum, this being purchased before 

 we had received the addition from Newport, making in all about 2,770 grammes of 

 metal, representing a money value of over eleven hundred dollars. 



In regard to the general arrangements of the rooms of the laboratory a full descrip- 

 tion will be found in the report of the Institution for 1881. The main room is fitted 

 with white-pine desks, one running across the entire width of the room against the 

 south wall, the other being placed against the third wall, besides which there are 

 cases for chemicals and apparatus, and a fume chamber. The balance room is hand- 

 somely fitted up with cases of black walnut and contains a heavy black walnut table 

 for the balances. The third floor of the building has also been fitted nj) during the 

 year with a substantial double desk. During the past year the supply of water has 

 been entirely insufficient, or rather the pressure has been insufficient, causing much 

 annoyance, the flow often ceasing for the greater part of the day ; and should the en- 

 gineer desire to fill his boilers no water can be had on the laboratory floor during the 

 process. Frequently the operation of distilling water for use in making analysis 

 had been suspended for lack of water to cool the condenser. To remedy this evil, 

 the chemist would suggest that a tank be placed on the roof of the building and con- 

 nected with the feed pump for the boilers in the engine room by a suitable arrange- 

 ment of valves; this could be so arranged as to supply the upper or third floor contin- 

 uously, being used on the second floor only when the ordinary supply should fail. 



DEPARTMENT OF EXPEEXIMENTAX PHYSIOLOGY. 



Mr. John A. Ryder, embryologist of the United States Fish Commis- 

 sion, has occupied during the year a laboratory fitted up for micro- 

 scopic work, and especially for embryological investigations, in the 

 Armory building, and has carried on several important investigations 

 upon the embryology of fishes and oysters. The laboratory has been 

 filled up with considerable completeness, chiefly at the expense of the 

 rish Commission. 



A list of Mr. Ryder's publications will be found in the appended bib- 

 liography. 



The Museum has furnished a considerable amount of material to Dr. 

 S. Weir Mitchell, of Philadelphia, who is engaged in investigating the 

 venom of the rattlesnake, and also a number of specimens to Dr. John 

 J. Mason, of Philadelphia, for his studies upon the brain. 



