May 1 8, 1888.] 



SCIENCE 



237 



for this preliminary work. Major Powell, who has probably stud- 

 ied the Rocky Mountain and arid region more carefully than any 

 one else, declares that the scheme is a perfectly feasible one, and 

 that the cost, though very great, will be but a small fraction of the 

 value of the land reclaimed. While the western portion of the 

 United States is not yet crowded when compared with Europe, or 

 even with other parts of our own country, it is no longer true that 

 "Uncle Sam is rich enough to give us all a farm." But, if 150,- 

 000 square miles of the arid lands of the United States could be 

 reclaimed, the limits of our agricultural development would be 

 ■enormously extended. 



Re-organization of the United States Fish Commission. 



The bill prepared by Professor McDonald, and introduced in the 

 House of Representatives, to re-organize the United States Fish 

 Commission and to define its duties, declares "that it shall be the 

 duty of the commissioner of fish and fisheries to continue the sys- 

 tematic investigation of waters of the United States, and of the 

 biological and physical problems they present, with the object of 

 determining the character, abundance, geographical distribution, 

 and economic value of the inhabitants of the waters, both salt and 

 fresh, as also their migrations, and the cause influencing or regulat- 

 ing the same. This investigation is to be conducted on a broad 

 and comprehensi\e plan, so as to arrive at the life-history of all 

 species having economic value, as well as those species to which 

 they are intimately and essentially related. 



" That he will continue the investigation into the history of the 

 methods and apparatus of the fisheries and for the preservation and 

 utilization of fishery products now in use, and will cause careful 

 study to be made of new methods and apparatus introduced from 

 time to time with the object of determining their effect upon pro- 

 duction, and furnishing the information upon which to frame intel- 

 ligent legislation regulating the conduct of the fisheries and improv- 

 ing their methods and apparatus. 



" That it shall*be the duty of the commissioner of fish and fisheries 

 to provide for the collection of the statistics of the fisheries of the 

 United States, especial reference being had to the fisheries of the 

 Great Lakes and of the New England and North Pacific coasts of 

 the United States, which are of international importance, and may 

 influence or become the subject of treaty stipulations. The statis- 

 tical inquiry hereby authorized and directed shall be comprehen- 

 sively planned to accomplish the purposes for which it is instituted. 



" That it shall be the duty of the commissioner of fish and fisheries 

 to continue the work of artificial propagation of food-fishes and 

 other useful inhabitants of the water with a view to their introduc- 

 tion into and establishment in the interior and coast waters, and 

 to the iTiaintenance and improvement of the important commercial 

 fisheries of the coast and interior lakes and rivers. To this end he 

 will, in his annual estimates transmitted to Congress, provide for 

 the maintenance and operation of the existing stations of the com- 

 mission, and for the maintenance and operation of such additional 

 permanent and field stations as may be from time to time authorized 

 and directed. 



" That the commissioner of fish and fisheries shall appoint such 

 employees as Congress may from time to time provide, with sala- 

 ries corresponding to those of similar officers in other departments 

 of the government, and he shall, as Congress may from time to 

 time provide, employ other persons, of e.xpert knowledge, for such 

 time as their services may be needed, including chemists, natural- 

 ists, and physicists, for the conduct of the researches and investiga- 

 tions required in the performance of the duties devolved upon this 

 department, or which may be from time to time authorized and 

 directed by Congress." 



HEALTH MATTERS. 



Contagion in Courts. — The State analyst of New Jersey, in 

 a recent trial, when called upon to take an oath as witness, avoided 

 kissing the Bible on the ground that he might contract disease by 

 so doing, saying, "So many different persons have kissed that 

 book, that 1 do not think it safe to touch my lips to it." The court 

 held that the witness must kiss the book, and he reluctantly did so. 

 This seems like a trifling matter, and yet it might be a serious one. 



The danger of contracting disease in this way is not imaginary. 

 Until courts so disinfect the Bible on which oaths are taken as to 

 make the act of kissing it safe, we would advise the practising of a 

 device which the writer has for years employed; viz., to kiss the 

 fingers with which he holds the book. 



Educating the White Blood-Corpuscles. — Dr. Ray 

 Lankester, in an address on ' The Struggle for Life ' {The Hospital 

 Gazette), in speaking of the function of the blood-corpuscles, said 

 that the corpuscles could be educated to deal with the bacteria, 

 and the future of preventive medicine would be the education of 

 the white blood-corpuscles. The fact that one man, by constant 

 use, could without injury take a dose of arsenic that would kill si.x 

 ordinary men, was due to the fact that he had by weakened doses 

 been educating and training the white corpuscles. They could be 

 taught to eat and flourish under conditions which, if not com- 

 menced gradually, would be destructive to them, and that was the 

 principle underlying protective inoculation. As« a preventive of 

 many fatal diseases in sheep and oxen, inoculation had been re- 

 markably successful. The corpuscles first received a weakened 

 breed of disease by inoculation, and thus when a violent attack 

 came they were ready to receive and dispose of it. This education 

 of the corpuscles, it seemed to him, was the explanation of the suc- 

 cess of vaccination. They received a weak dose of the poison from 

 the vaccine, and were in that way prepared for a stronger dose in 

 the way of small-pox. He believed the white corpuscles could be 

 trained to receive the most virulent poisons, and he hoped this 

 training would be carried on so as to deal with a great number of 

 diseases. 



ELECTRICAL SCIENCE. 



Sir William Thomson's Electrical Measuring-Instruments. 



For some years past Sir William Thomson has been working on 

 electrical measuring-instruments with a view to perfecting some 

 means of accurately and easily measuring the heavy currents and 

 the potentials used in commercial work. Mr. J. A. Fleming, in 

 Industries, describes the latest forms Sir William has produced. 

 The ammeters are six in number. The different types are, — 



The Centi-ampere 



balance fron: 



1 I to 



50 centi 



-amperes 



'' Deci-ampere 







I " 



50 deci- 



amperes 



" Ampere 







,\' " 



25 ampt 



^res 



" Deka-ampere 







2 " 



100 





" Hekto-ampir! 







10 '■ 



500 " 





" Kilo-ampere 







50 " : 



2.500 " 





All of these instruments are on the same general plan. The attrac- 

 tion between two coils carrying the current — one movable, the 

 other fixed — is balanced by a weight sliding on a scale-beam. 

 Heretofore the difficulty in such an arrangement has been in getting 

 heavy currents to the movable coil without greatly decreasing the 

 sensitiveness of the apparatus. In these instruments there are two 

 movable coils, fastened on the two ends of a light frame, and below 

 each of them is a fixed coil. The frame has an. axle in the middle 

 by which it is suspended, and it is in the suspension that the chief 

 novelty and improvement lie. The axle ends in two semi-cylindri- 

 cal trunnions. Above them are two similar fixed trunnions. The 

 two sets are connected by a number of extremely fine copper wires 

 bearing on the rounded surfaces of the lower trunnions. This ar- 

 rangement allows a free though limited movement of the frame, 

 and the numerous fine wires will carry a heavy current. The wind- 

 ing of the two coils are such that one end of the frame is repelled, 

 the other attracted, when a current passes. There is a scale-beam 

 attached to the frame, and a weight moving on this is shifted until 

 the frame is horizontal. The reading on the beam opposite the 

 weight gives the current that is flowing. The great advantage 

 of this arrangement, as in other forms of electro-dynamometer, 

 lies in the fact that the readings are independent of any change 

 in the strength of magnets, such as are used in ordinary com- 

 mercial measuring-instruments, and also of the value of the 

 earth's magnetism. The instruments, however, are not so portable 

 as many other forms, and are somewhat difficult to adjust. They 

 will be useful for standardizing the ordinary forms of voltmeter and 

 ammeter. 



