ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 347 



tions of different organisms to be used in a mixed vaccine. It is based 

 on the fact that when blood-corpuscles, washed free from fibrin and 

 serum, are treated with emulsions of various bacteria with which the 

 blood has previously been in living contact, haemolysis occur with them, 

 and with no others. The greater the haBmolytic action, the greater the 

 proportion of that organism that must be used in the subsequent treat- 

 ment. Minute test-tubes (30 by 3 mm.) are arranged on plasticine and 

 numbered. In each tube are placed 0*1 cm. of 5 p.c. emulsion of the 

 patient's blood-corpuscles. To successive tubes is added O'l cm. of 

 bacterial emulsion from the stock series. Incubate for ten minutes. 

 The tubes in which haemolysis has occurred are noted. The incubation is 

 repeated for periods of ten minutes up to one hour. The hfemolytic 

 power of the various strains is thus relatively determined. A control 

 with normal saline is needed, as a guide to variations of haemolysis due 

 to the salt-content of the blood. Graded quantities of vaccine will be 

 prescribed according to results. 



Cultivation of Green Algae.* — J. B. Petersen obtained pure cultures 

 of green algai on gelatin to which the following inorganic salts were 

 added : — Nitrate of calcium 1*5 grm., chloride of potassium O'o grm., 

 sulphate of magnesium 0*5 grm., phosphate of potassium (KHo PO,,) 

 5 grm., chloride of irou, a trace. The water in which the foregoing in- 

 gredients was dissolved was 1000 grm., and the gelatin 100 grm. The 

 algse which prospered on this medium were Stichococcm minor, Chlorella 

 ellipsoidea, and Coccomyxa Niigeliana. Later, the author used an agar 

 base, as follows: — Agar 15 grm., KNOo 1 grm., MgS04 0*25 grm., 

 K2HPO4 0*25 grm., distilled water 1000 grm. This medium was placed 

 in Petri's capsule, and the algse sprayed over the surface. The author 

 then refers to Hedland's method of cultivating algte on slides. 



Blood-cultures on Dried Bile.t — A. Le Boeuf and P. Braun find 

 that dried bile is just as good for cultivation purposes, and much more 

 convenient. The fresh bile is sterilized at 125° C. for thirty minutes, 

 then filtered through Chardin paper or cotton-wool. The filtrate in a 

 flat vessel is inspissated by means of a water-bath. After cooling, the 

 mass hardens, becomes friable, and is easily pounded up in a mortar. 

 1 grm. of the dried and powdered bile corresponds to about 10 c.cm. 

 of liquid bile. 1 grm. of the dried bile is placed in a test-tube ; it is 

 then again autoclaved, and while still warm slopes are made. To make 

 a blood-culture, 5 c.cm. of blood are poured into the tube containing bile. 

 The blood dissolves the bile, and the tubes are placed in an incubator 

 and the growth examined later. Like solmedia shown before the 

 Society, it is very convenient to use, easy of transport, and of necessity 

 is easily soluble. 



* M6m. Acad. Roy. Sci. et Let. Denmark, Sect. Sciences, xii. (1915) pp. 272-379 

 (4 pis.). 



t C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 212-6. 



