456 ANNUAL REPORTS OP DEPARTMENT OF AGRICULTURE. 



at the request of the Department of Justice and in collaboration with 

 the Bureau of Forestry. Durin^ the past year the Department of 

 Justice has not rcq^uired any work along this line, but the laboratory 

 has been engaged m an investigation of the sulphur trioxid content 

 of the foliage of trees which are killed otherwise than by smelter 

 fumes. 



MICROCHEMICAL EXAMINATIONS. 



INVESTIGATIONS. 



While the microchemical work has been continued along similar 

 lines as in former years, certain investigations have been made which, 

 together with the increased demands for examinations under the food 

 Ir.w, have taxed the facilities of the laboratory severely. wSeveral 

 lines of special investigation conducted during the year are worthy 

 of special notice. 



The field work on the subject of egg desiccation and freezing, which 

 was under way at the end of the last fiscal year, was continued. 

 Many factories engaged in the business of candling and breaking 

 out of eggs were visited, the methods employed closely observed, 

 and the products obtained examined, thus providing each sample 

 with an authentic history. 



The work on the microchemistry of alkaloids has been continued, 

 a few more having been studied, together with some new combina- 

 tions. Many of the combinations studied have been photographed 

 for reference purposes, and frequently the data have been called into 

 use in connection with the examination of drugs and drug products 

 under the law. 



The work on ketchup was continued during the last pacldng 

 season, during which time a number of factories were visited for the 

 purpose of studying the use of decayed or decomposed tomatoes in 

 this product. It is well known that some factories have made up 

 very badly decayed tomatoes or trimmings into ketchup, and it 

 was for the purpose of studying the products of such practices for 

 comparison with the good product that the study was made. The 

 consuming public is usually unable by taste to judge of the character 

 of the raw stock used for some of this cheap product because of the 

 boihng, and the incorporation of spices and vinegar serves to mask 

 to all except an expert the original character of the raw stock. The 

 experience and knowledge gained during tliis inspection has been 

 of great value in dealing with products of this kind under the food 

 and drugs act. A somewhat similar study was begun during the 

 last part of the year on other decayed fruit products to provide a 

 basis for judgment when they were found in the manufactured form. 



In passing upon malt sprouts as cattle food under the food and 

 drugs act it developed that a knowledge of manufacturing methods 

 and practice should be obtained, and for this purpose a member of 

 the laboratory visited three of the malting centers of the Middle 

 West and visited factories, observing the methods used and obtaining 

 for examination representative samples from the various factories. 

 The results obtained will be used in passing on the adulteration of 

 such products. 



Insect powder is obtained by grinding the flowers of the pyrethrum 

 plant. In connection Avith the anticipated enforcement of the 

 insecticide law, the question of the amount of stems to be permitted 



