1104 SUMMAEY OF CUEEENT EESEAECHES EELATING TO 



300 cmm. If it is desired to obtain a sediment without loss Beudant's 

 method should be adopted. In this, two watch-glasses, one placed at 

 a higher level than the other, are made use of. The upper one con- 

 tains the fluid to be filtered, and the two are connected by means of 

 a moistened strip of filter-paper. This auto- 

 FiG. 261. matic action may be further increased if it be 



desirable to wash the filtrate. This is effected 

 by a third watch-glass, filled with distilled 

 water, and placed above that which contains the 

 substance to be washed. 



For filtering very small quantities Dr. K. 

 Haushofer recommends two glass tubes, a, h, 

 fig. 261, placed in vertical apposition, and con- 

 nected by a screw-clamp E which allows the 

 upper tube to be approximated to or removed 

 from the lower one. From the lower tube 

 another, c, projects upwards at an angle. Be- 

 tween the two tubes at d, a sheet of moistened 

 filter-paper is inserted, and the tubes are then 

 closely adjusted by means of the screw. The 

 bottom of the tube h is closed by a stopper k. The fluid is then 

 poured in, and suction made at the side tube. The filtrate is always 

 perfectly clear, and the residue is collected in a small space. 



Examining Blood in Typhoid Fever.* — Mr. T. S. Ealph states 

 the results of his experiments on blood with phloroglucen, phosphoric 

 acid, ozonic ether, and hydrocyanic acid. 



With normal blood, phloroglucen causes the corpuscles to separate 

 into a larger greyish solid portion and a smaller fluid residuum, pre- 

 senting one or more spots of a reddish hue. A similar but less 

 decided effect is produced by the action of phosphoric acid. Ozonic 

 ether causes an active effervescence, followed on its cessation by the 

 appearance of numerous large cells varying in size from 1/2000 to 

 1/1000 of an inch. Each of these cells contains a small vesicle or 

 gas-bubble of a reddish or orange hue. By the action of hydrocyanic 

 acid on dry films of blood, the presence of minute reddish or orange- 

 coloured spots may be detected. These increase in size, vary in 

 number, may be arranged in circles, or may be replaced by larger ones. 



Similar changes can be brought about in typhoid blood by the 

 use of these reagents, but typhoid blood examined without the aid of 

 chemical agents presents under ordinary circumstances orange and 

 red vesicular forms imbedded in the plasma. These vary in size from 

 1/10,000 to 1/7000 of an inch in diameter, are mobile, and surrounded 

 by a white halo-like appearance. The action of ozonic ether and 

 other reagents appears to release orange-coloured vesicular forms in 

 a more permanent condition and in larger numbers than in healthy 

 blood. Hydrocyanic acid is stated to produce certain appearances 



* Ealph, T. S., ' Microchemical Observations on the Blood in Health and in 

 Typhoid Feveiy 12 pp. (1 pi.), 8vo, Sydney, 188.5, 



