Journal of Applied Microscopy. 



185 



cult, to ask questions leading him to find 

 them for himself. But even with the best 

 book in hand, the teacher is indispen- 

 sable to the student, and in the hands 

 of any live teacher this little book will 

 prove useful in many schools. 



While scarcely suitable for high school 

 work, there is much to recommend the 

 manual for use in normal schools, and 

 for more advanced students, where 

 training may be less the object than is 

 the accumulation of information; and as 

 a pioneer in its line we heartily wish it 

 success. 



L. Muni'.AcH. 



Detroit, Mich., September, 1898. 



Micro-organisms and Sterilizing Processes 

 in the Canning Industries. Souring ot 

 Canned Sweet Corn. S. C. Prescott and 

 W. Lyman Underwood, Technology Quar- 

 terly Vol. XI, No. 1, 1898. 



The canning industry, like many other 

 technical processes, has grown up in a 

 purely empirical way. The methods that 

 are used are the results of pure experi- 

 ence. Too frequently, scientific methods 

 are not considered, and as a result con- 

 siderable losses are occasioned that might 

 readily be prevented if modern methods 

 based on scientific research were insti- 

 tuted. The present paper takes up a 

 phase of an important industry. Its suc- 

 cessful operation depends upon the fulfill- 

 ment of biological laws. After describ- 

 ing the history of the growth of this 

 industry, the authors take up the ques- 

 tion of the souring of corn, and show 

 that this defect is always associated with 

 bacterial action and imperfect steriliza- 

 tion. They isolated a number of different 

 species from spoiled corn, and they also 

 showed that these same forms were to 

 be found on the kernels and beneath the 

 husks as it comes from the field. The 

 failure of the corn to keep comes from 

 insufficient sterilization. When the filled 

 can is heated up even in a steam appar- 

 atus under pressure, the temperature of 

 the interior of the can does not equal that 

 of the outside unless the exposure iS 

 prolonged. Thus, in sterilizing the cans 

 for an hour, the interior is subjected to 

 the proper sterilizing temperature for 

 only five minutes.. This exposure is too 

 short. A temperature of 250 degrees F. 

 for ten minutes is sufficient to produce 

 perfect sterilization. The use of the 

 intermittent method of sterilizing or an 

 open water bath was found to be imprac- 

 tical. The losses which are occasioned 

 annually from these unscientific methods 

 show the necessity of a dissemination of 

 knowledge pertaining to the biology of 

 these problems. 



H. L. Russell. 

 University of Wisconsin. 



NEWS AND NOTES. 



Minor notes on technique, personals, news items, 

 notices of meetings of societies, conventions, etc., 

 will be received up to the twenty-second of the 

 month preceding issue. 



"Two thousand Red Corpuscles of Hu- 

 man Blood measured by F. J. Parker in 

 the Pathological Laboratory of the Medi- 

 cal Department of Yale University, un- 

 der the supervision of Prof. M. C. White, 

 M. D."* 



Each specimen of blood was spread 

 upon a slide and quickly dried and cov- 

 ered with thin glass. Measurements were 

 made by a Zentmayer filar micrometer 

 rated by a Zeiss stage micrometer divided 

 to one-hundreths of a millimeter. 



First, 500 corpuscles were measured 

 fi'om an American girl seventeen years 

 old. The average diameter of the 500 

 measured was 7.90 mikrans; largest cor- 

 puscles, 9.11 mikrons; smallest corpuscle, 

 6.72 mikrons. 



Second, 500 corpuscles from an Italian 

 boy, 17 years old, who had been in Amer- 

 ica three months. Average diameter of 

 the 500 measured was 7.99 mikrons; 

 largest corpuscles 9.25 mikrons; smallest 

 corpuscle 6.78 mikrons. 



Third, 500 corpuscles from a girl from 

 Finland, 25 years old, who had been in 

 the United States five months. Average 

 diameter of 500 corpuscles measured 7.S9 

 mikrons; largest, 9.80 mikrons; smallest, 

 6.65 mikrons. 



Fourth, 500 corpuscles from Miss Aw- 

 chee, an Esquimax girl, who had been in 

 New York about four months, age about 

 12 years. Average diameter of 500 cor- 

 puscles measured 8.07 mikrons; largest 

 corpuscle, 9.52 mikrons; smallest, 6.65 

 mikrons. 



In all cases the measurements were 

 taken to include all of the dark border 

 of the corpuscle, the corpuscle being 

 pinched between the two spider lines of 

 the micrometer. 



These measurements do not favor the 

 statements of Gram as quoted by Cabot 

 in his book on the blood, that the inhabi- 

 tants of Northern Europe have a larger 

 average diameter of red blood corpuscles 

 than those of Italians and Germans. 



M. C. W. 



*After concluding his measurements. Dr. 

 Parker entered the Naval service of the 

 United States, before he had time to write 

 this report in detail. 



Prof. T. W. Edgeworth David, B. A.. 

 F. G. S., of Sidney University, New 

 South Wales, has recently made some 

 very important and interesting discov- 

 eries of radiolaria in early Palaeozoic 

 rocks in New South Wales. In the New 

 England district they are found in red 



