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scientific work, and to exhibit something of the spirit which 

 instigates and controls the scientific worker. 



And first, all truly scientific work aims at exactitude. The 

 great majority of people are hopelessly inexact. It is true that 

 in dealing with dollars and cents, business men, and indeed 

 most men, are precise in their reckonings, but in a thousand 

 and one other things they are careless as to matters of fact. 

 If we look carefully at this matter, we shall find that many of 

 the annoyances of life come from a carelessness in this respect 

 a want of accuracy. The habit has not been cultivated. Now 

 workers in any scientific field know full well the necessity for 

 preciseness. Terms must be correctly used ; observations must 

 be made with precision, and facts must be truly stated. Look 

 at the scientific papers in a journal or volume of transactions 

 which publishes the result of original investigations, and ob- 

 serve how concise the language, how precise the statements. 

 There is no diffuseness in the style, no approximations nor 

 guess-work where exact statement is possible. Accuracy as a 

 habit is opposed to all slovenliness, and to all hap-hazard meth- 

 ods of statement and of work. Young men before entering 

 upon other business pursuits are often placed in banks that they 

 may learn with what rigid exactness money is handled and ac- 

 counts are kept, and with a view to a similar kind of training 

 in another direction, I would have students who propose follow- 

 ing professions make thorough study of some one of the natu- 

 ral sciences, acquiring in the laboratory, museum or work-room 

 the habit of exact observation and precise measurement and 

 statement in such way that it will stick to them for life. And 

 surely there is no calling in which this habit is more essential 

 than in that in which you are engaged. Study the United 

 States Pharmacopoeia, and observe the preciseness of statement 

 throughout, and yet in the following of its explicit directions 

 how many mistakes are made. A single illustration will suffice. 

 I have recently examined a large number of samples of diluted 

 acetic acid procured from retail drug stores in different parts of 

 this State. It is not a very important preparation, perhaps, but 

 It is a very simple one, and easily made, according to the direc- 

 tions of the Pharmacopoeia, by dilution of the stronger acid, 

 and yet of these samples not one quarter were properly made, 

 the remainder varying from a third to five times the proper 

 strength. In the preparation of such an article, absolute pre- 



