PEOCBEDINGS FOE 1888. XXV 



Our public system of Analysis of Foods has now been in operation fi)r a number of years, and the 

 W(jrk done by our official analysts is being more fully appreciated by the public at large, as its real 

 nature and objects become more generally known, ;u)d as the system itself becomes recognized iw a 

 means conducive to public health and comfort, and of securing honesty in commercial transactions. 

 The methods by which the determinations are made — the jjrocesses of analysis, as they are called — 

 ai'C being improved and systematized from time to time, and their degrees of accuracy experimentally 

 ascertained. Where the results of scientific investigations are liable to form the basis of proceedings 

 before civil or criminal courts, or are needed to supply the evidence for the prosecution of judicial 

 enquiries, it is obvious that two conditions are very desirable, if not in all cases absolutely necessary: 

 (1) that the methods of investigation should be such as to yield results of known accuracy, with defi- 

 nitely ascertained limits uf ci-ror; (2) that these methods, and the manner in which the results are 

 obtained, should be capable of clear and simple explanation, intelligible to judges, juries and the pub- 

 lic, as well as to experts, so far as necessary to enable their exact probatory value to be understood. 

 Such considerations prepare us for aj^preciating the imjwrtance of the cai-eful testing and comparing 

 of processes that are being constantly pursued in the laboratories of our public analysts. The paper 

 of Ml-. Anthony McGill, gives some idea of the elaborate nature of the investigations needful for 

 obtaining tests sufficiently precise even to enable the analyst to reach a satisfactory conclusion in 

 regard to what may seem to many to be a very simj^le matter, the purity of our morning cup of 

 cofTee. Mr. Maefarlane and Mr. Ellis follow this up with accounts of methods of Milk Analysis, and 

 then comes Dr. Euttan's paper on the Digestibility of certain varieties of Bread, an experimental 

 study of what has long been known to experts as " the alum question." Those who have watched the 

 history of the adulteration of articles of food and drink since the daj-s when Dr. Hassall first aroused 

 the people of England to its enormitj^ some forty years ago, will know how much attention has been 

 given to this one special subject of the use of alum in bread, the effect of alum being, it is alleged, to 

 produce an apparently pure loaf from defective flour. It appears from Dr. Euttan's researches that 

 the decomposition of both phosphate and alum baking powders results in the formation of salts which 

 decidedly retard the action of the digestive ferments; that the alum salts produced are of greater 

 retarding power than the phosphates, and that both exercise a marked retardation over tartaric 

 acid. These results remind us of the employment of certain tartarates in medicine, and of the bene- 

 ficial effects experienced from the use of fruits and vegetables containing acid tartarates. As ingre- 

 dients in bread, resulting from the use of baking powders, alkaline sulphates and phosphate of 

 alumina are regai'ded as most injurious. 



The Flow of the Sap is a phenomenon that engaged the attention of vegetable physiologists at a 

 time when the knowledge of plant structures and functions was but imperfect. Other questions 

 arising withdrew attention from it, and left experimental work still to be done. Dr. Harrino-ton's 

 paper will again call attention to this subject. He gives a series of tabulated experiments on the 

 flow of the saccharine sap of the ash-leaved maple, made on two trees growing not far from McGill 

 College, Montreal, showing the season of sap-flow, and the effects of temperature, etc., upon it, from 

 day to day. 



Mr. A. P. Coleman's paper on the Microscopic Petrography of the Drift of Central Ontario appeals 

 to the geologist on behalf of a form of investigation that may have been too much neglected, and 

 indicates scope for still more extended observation. 



Mr. Bovey, the active Secretary of the Canadian Institute of Civil Engineers, has communicated, 

 through Dr. Johnson, the results of an investigation as to the Maximum Bending Moments at the 

 Points of Support of continuous Girders of n Spans. Mr. Bovey's name having been subsequently 

 added to our membership, we may confidently hope that this important paper will be followed by 

 the results of other mathematical and phj^sical researches tending to practical utility, so important 

 in a country like ours actively engaged in works of construction. 



The fourth Section, Geological and Biological Sciences, is opened by Abbé Laflamme's 



Proc. 1888. D. 



