EXPERIMENT STATION REPORTS. 283 



"A bottle containing a 10% solution of Rochelle salt, potassium and 

 sodium tartrate, was sent in to determine the cause of the brownish- 

 black growths found in it. Cultural methods and microscopical exami- 

 nation showed the presence of two molds, a Penicillium and an uniden- 

 tified pink mold. (Zae Northrup). 



Miss Northrup also submits an initial report on bacteriological can- 

 ning problems for year 191G-1917 : 



"This past year studies have been made on spoiled canned goods both 

 domestically and commercially prepared. The few samples of home 

 canned goods analyzed were miscellaneous vegetables and fruits canned 

 by the cold-pack method in glass 'self-sealer' cans. Most of the canned 

 foods examined were commercial goods (canned in tin) and the 'spoiled' 

 cans analyzed have been either 'swells' or 'springers.' On account of the 

 difficulty in obtaining samples of spoiled home-canned foods for investi- 

 gation arrangements were made with the wholesale grocers in Lansing 

 to furnish our laboratory with any spoiled cans which they happened to 

 have. In this way we have obtained quite a number of samples of dif- 

 ferent vegetables and fruits for analysis. 



"Analyses are made to determine the number of aerobic and anaerobic 

 microorganisms per cubic centimeter in the liquid, the gases quantita- 

 tively and qualitatively and the reaction of the liquid. Direct micro- 

 scopical examination is made of the liquid to determine the presence of 

 microorganisms. When found by cultural methods, they are isolated 

 and studies necessary for their identification are made ; their resistance 

 to heat and to acids is also determined, in fact every effort is made to 

 see whether these organisms have anything to do with the particular 

 type of spoilage in the food from which they are isolated. 



"Many cans have proved to be sterile. This may not be a correct 

 statement, however, as the methods emploj^ed for analyses with these 

 particular cans may not have been the right ones. This is one of the 

 difficulties to be overcome. 



"Bacteria have been isolated from spoiled cans of commercially pre- 

 pared fruits and vegetables. In some cases it has been possible to repro- 

 duce spoilage, i. e. 'swells' by inoculating a sterile can of a fruit or vege- 

 table with the organism obtained from a spoiled can of the same fruit or 

 vegetable. Enough work has been done already to show us many faults 

 in the methods, consequently at present we are attempting to perfect our 

 apparatus and technic. Mr. Leroy W. Mailman, Miss Elsa Schueren 

 and Mr. Glen I. Blades have contributed largely to the production of 

 the data obtained. 



"A completely equipped canning kitchen has been installed in the 

 basement of our laboratory and in cooperation with Mr. Lindemann 

 and Miss Cowles, who are going to do experimental work in canning, 

 we expect to learn at first hand some of the problems of the home can- 

 ner with the advantage that data will be obtainable on every stage of 

 the process." (Zae Northrup). 



Mr. Charles G. Nobles submits the following report: 



"The past year has been spent with two phases of work with nodule 

 forming bacteria, the production and distribution of cultures and inves- 

 tigation or experimental work. During the spring from April 1st to 

 July 1st my time has been given over almost entirely to the details of 

 preparation of media, inoculation and disj)Osal of the cultures. 



