222 METHODS FOR THE ANALYSIS OF GASTRIC JUICE 



made in the same manner as this one, that is introduced at 88 C. 

 The tubes thus prepared should be again checked up with the 

 standard to see that no mistake has been made. 



(2) Rose's Modification l of the Jacoby-Solms Method. 2 

 Dissolve 0.25 gm. of the globulin of the ordinary garden pea, 3 

 Pisum sativum, in 100 c.c. of 10 per cent sodium chloride solution, 

 warming slightly if necessary. 4 Filter and introduce 1 c.c. of the 

 clear nitrate into each of a series of six 5 test-tubes about 1 cm. 

 in diameter. Introduce into each tube 1 c.c. of 0.6 per cent 

 hydrochloric acid and permit a period of about five minutes to 

 elapse for the development of the turbidity. Make a known 

 volume of the gastric juice (5 to 10 c.c. is sufficient) exactly 

 neutral to h'tmus paper with dilute alkali; and record the volume 

 of the alkali so used. If acid metaprotein precipitates, filter it 

 off; if there is no precipitate proceed without filtration. Dilute 

 the clear neutral solution with a known quantity of distilled water 

 (usually 5 volumes) making proper allowance for the volume of 

 alkali used in the neutralization. Boil 5 to 10 c.c. of the diluted 

 juice, filter and add the following decreasing volumes (c.c.) to the 



1 Rose: Arch. Int. Med., 1910, 5, 459. 



2 Solms: Z. f. klin. Med., 1907, 64, 159. 



z The globulin may be prepared as follows: "The finely ground peas, 

 freed as much as possible from the outer coating, are repeatedly extracted 

 with large quantities of 10 per cent sodium chloride solution, the extracts 

 combined, strained through fine bolting-cloth, and allowed to stand over 

 night in large cylinders to deposit insoluble matter. The supernatant fluid 

 is siphoned off and saturated with ammonium sulphate. The precipitate 

 of albumin and globulin is filtered off, suspended in a little water, and dialyzed 

 in running water for three days, until the salt has been removed, and the albu- 

 mins have been dissolved. The globulins are filtered off and washed two 

 or three times to remove the last trace of albumins. To purify further, 

 the precipitate is extracted with 10 per cent sodium chloride solution, and 

 filtered until perfectly clear. The resulting solution is neutralized to litmus 

 paper by the cautious addition of dilute sodium hydroxide, and again dialyzed 

 in running water for three days to remove the salts completely. The pre- 

 cipitated globulins are then filtered off and dried on a water-bath at 40 C. 

 During the entire process of separation the proteins should be preserved 

 with a mixture of alcoholic thymol and toluol." This dried globulin is used 

 in the clinical procedure. 



4 This solution may be preserved at least two months under toluene. 



6 A longer series of tubes may be used if desired. However, experience 

 has shown that a series of six ordinarily affords sufficient range for all diag- 

 nostic purposes. 



