154 Dr. W. Roberts. Estimation of the Amylolytic [May 5, 



diastasic agent which is present in urine, and presumably to all dias- 

 tasic solutions. In the case of solid preparations containing diastase 

 like malt or glandular tissue — a solution in known proportions must 

 first be prepared ; and from the ascertained activity of such solution 

 the proportionate activity of the solid substance can be easily calcu- 

 lated. I may here mention some of the results which this method has 

 already yielded. 



Pancreatic Tissue. — The pancreatic tissue of the pig (obtained from 

 animals killed for the market in the fasting state) yielded an extract 

 which, when made on the large scale, possessed a mean diastasic value 

 of 100. This extract is sent out by Mr. Benger, of the firm of 

 Mottershead and Co., Chemists, Manchester, under the name of 

 "Liquor Pancreaticus," and is made in the proportion of one part of 

 pancreatic tissue to four of solvent (water containing 25 per cent, 

 rectified spirit). This value indicates that 1 grm. of the moist pan- 

 creas of the pig is capable of transforming 4 grms. of dry starch to 

 the point at which it no longer gives a colour reaction with iodine, in 

 five minutes, at a temperature of 40° C. 



The pancreatic tissue of the ox and sheep yielded an extract (made 

 in the same proportions) which was of far inferior activity. The ox 

 extract had a diatasic value of about 11 and that of the sheep of about 

 12. These numbers indicate that in point of diastasic activity the 

 pancreas of the pig has ten times the value of the pancreas of the ox 

 and sheep. This extraordinary difference is probably linked with the 

 diversity of their food. The pig is fed largely upon potatoes and 

 meal, which are rich in starch ; the ox and sheep, on the other hand, 

 feed on grass, which is poor in starch. We shall presently find that 

 there is no such difference in regard to tryptic activity in the pancreas 

 of these animals. 



Human Saliva. — Filtered saliva was found to have a diastasic value 

 varying from 10 to 17 at 40° C. Its action was influenced by tempera- 

 ture exactly in the same manner as that of pancreatic extract. It 

 increased in energy up to about 30° C, continued steady from this 

 point to about 45°, and then declined, being finally extinguished 

 between 65° and 70°. 



Malt Diastase. — Infusions of malt made in the proportion of one part 

 of crushed malt to four parts of water, exhibited a diastasic value of 

 4 to 5 at 40° C. But malt diastase did not attain its maximum activity 

 at this temperature. It continued to increase in energy up to about 

 60° C, when it showed a diastasic value of 10. Above 60° the action 

 diminished in energy, but did not come to a full stop until the tempera- 

 ture approached 80° C. 



Human Urine. — Several specimens of healthy urine were tested by 

 this method. They showed a diastasic value varying from 0*03 to 0'13 

 at 40° C. The effect of temperature thereon was not examined. 



